Available via license: CC BY 4.0
Content may be subject to copyright.
EDITORIAL
Climate resilient crops for improving global food
security and safety
Abstract
Food security and the protection of the environment are urgent issues for global society, particularly with the uncertainties of
climate change. Changing climate is predicted to have a wide range of negative impacts on plant physiology metabolism, soil
fertility and carbon sequestration, microbial activity and diversity that will limit plant growth and productivity, and ultimately
food production. Ensuring global food security and food safety will require an intensive research effort across the food chain,
starting with crop production and the nutritional quality of the food products. Much uncertainty remains concerning the resil-
ience of plants, soils, and associated microbes to climate change. Intensive efforts are currently underway to improve crop
yields with lower input requirements and enhance the sustainability of yield through improved biotic and abiotic stress
tolerance traits. In addition, significant efforts are focused on gaining a better understanding of the root/soil interface and
associated microbiomes, as well as enhancing soil properties.
1|INTRODUCTION
The United Nations Sustainable Development Goals (SDGs) present
an urgent and formidable challenge to scientists and society alike,
highlighting the urgent requirement to transform agriculture and the
food sector to achieve food and nutrition security, ecosystem sustain-
ability, economic growth, and social equity over the coming decades.
Global food demand is predicted to grow by 70–85% as the popula-
tion increases to over 9 billion people by 2050 (FAO, 2017; Ray,
Mueller, West, & Foley, 2013). A “next generation Green Revolution”
is required to achieve future food security. Radical new concepts
and approaches are needed to achieve a more sustainable develop-
ment of agriculture. The next Green Revolution requires a much
broader and systems‐based approach including environment, econ-
omy, and society, across all levels of organization (Nüsslein &
Dhankher, 2016). Transformative science across the agri‐food sector
is required if a major crisis in food production to meet the needs of a
growing world population is to be avoided. Future agriculture requires
tailored solutions that not only incorporate fundamental step‐changes
in current knowledge and enabling technologies but also take into
account of the need to protect the earth and respect societal demands.
Climate change has far‐reaching implications for global food secu-
rity and has already substantially impacts agricultural production
worldwide through effects on soil fertility and carbon sequestration,
microbial activity and diversity, as well as on plant growth and produc-
tivity. Negative environmental impacts are exacerbated in current
cropping systems by low diversity and the high intensity of inputs,
climate‐associated yield instabilities being higher in grain legumes such
as soybean (Figure 1) and broad leaved crops than in autumn‐sown
cereals (Reckling et al., 2018). The predicted increased frequency of
drought and intense precipitation events, elevated temperatures, as
well as increased salt and heavy metals contamination of soils, will
often be accompanied by increased infestation by pests, and patho-
gens are expected to take a major toll on crop yields (Figure 2) leading
to enhanced risks of famine (Long, Marshall‐Colon, & Zhu, 2015). For
example, the frequency and intensity of extreme temperature events
in the tropics are increasing rapidly as a result of climate change. Trop-
ical biomes are currently experiencing temperatures that may already
exceed physiological thresholds. The ability of tropical species to with-
stand such “heat peaks”is poorly understood, particularly with regard
to how plants prevent precocious senescence and retain photosynthe-
sis in the leaves during these high temperature (HT) conditions. Such
environmental stresses are among the main causes for declining crop
productivity worldwide leading to billions of dollars of annual losses.
Throughout history, farmers have adopted new crop varieties and
adjusted their practices in accordance with changes in the environ-
ment. But with the global temperatures rising, the pace of environ-
mental change will likely be unprecedented. Furthermore, with the
expansion of crop cultivation to nonoptimal environments and nonar-
able lands, development of climate‐resilient crops is becoming increas-
ingly important for ensuring food security (Kathuria, Giri, Tyagi, &
Tyagi, 2007).
--------------------------------- -- --- -- --- -- -- --- -- --- -- --- -- -- --- -- --- -- -- --- -- --- -- -- --- -- --- -- -- --- -- --- -- --- -- -- --- -- --- -- -
This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided
the original work is properly cited.
© 2018 The Authors Plant, Cell & Environment Published by John Wiley & Sons Ltd
Received: 23 March 2018 Accepted: 28 March 2018
DOI: 10.1111/pce.13207
Plant Cell Environ. 2018;41:877–884. wileyonlinelibrary.com/journal/pce 877
Sustainable innovation of the agricultural sector within SDG
constraints is urgently required to improve the way that food and
animal feed are produced. Current scientific advances offer considerable
potential to meet the challenges of increasing agricultural production with
conservation of the environment and the earth's ecosystems, compliant
to the SDGs. The papers published in this special issue cover basic and
applied research focused on enabling crops to grow under over a wider
range of environmental conditions with sustainable and reliable crop
yields. Particular emphasis is placed on the development of climate‐resil-
ient crops that are able to adapt rapidly to changing climatic conditions
and on how climate change impacts on the resilience of plant/soil inter-
face and soil microbiomes. The manuscripts that comprise this volume
address the challenges imposed by the increased frequency of abiotic
and biotic stresses with a view developing strategies to minimize the
impact of changing climate on agriculture and the environment.
1.1 |Abiotic stress tolerance
Of the multitude of diverse abiotic and biotic stresses faced by plants
in the field, water availability is widely accepted to be one of the most
important constraints to crop yields. Drought stress alone is expected
to limit the productivity of more than half of the earth's arable land in
the next 50 years, competition for water between urban and agricul-
tural areas compounding the problem. Several papers in this volume
(Herzog, Konnerup, Pedersen, Winkel, & Colmer, 2017; Kerr et al.,
2017; Pérez‐Jiménez, Hernández‐Munuera, Piñero, López‐Ortega, &
Amor, 2017) describe the physiological, molecular, and biochemical
responses of plants to drought and flooding. Although the use of
brackish and saline water could help alleviate the world's water prob-
lems, this option is only possible with the development of salt‐tolerant
crops (Figure 3) or management practices that alleviate salt stress. A
number of manuscripts in this volume (Herzog et al., 2017; Joshi
et al., 2017; Lakra, Kaur, Anwar, Pareek, & Pareek, 2017; Oyiga
et al., 2017; Patishtan, Hartley, Fonseca de Carvalho, & Maathuis,
2017) describe how plants tolerate high levels of salt. Soil
phytoremediation and tolerance to heavy metals are also highlighted
(Fasani, Manara, Martini, Furini, & DalCorso, 2017). A number of
papers describe the mechanisms that enable plants to withstand
extremes of temperature (Bredow, Tomalty, Smith, & Walker, 2017;
D'Amelia et al., 2017; Djanaguiraman et al., 2017; Djanaguiraman,
Perumal, Ciampitti, Gupta, & Prasad, 2017; Charrier, Isabelle, Marc,
& Thierry, 2017; Izydorczyk et al., 2017; Xia et al., 2017). Taken
together, the new information provided in these manuscripts increases
our current understanding of the biochemical and molecular basis of
crop adaptation to abiotic stresses, highlighting promising candidate
genes/enzymes that are targets for manipulation to improve the ability
of plants to produce better yields under changing climate conditions.
The acclimation mechanisms that facilitate optimization of photosyn-
thesis and associated processes to changing irradiance are considered
in two papers (Karpinska et al., 2017; Townsend, Ware, & Ruban,
2017). Within this context, the stress‐induced accumulation of reac-
tive oxygen species (ROS) controls numerous growth and develop-
mental processes by modifying enzyme activity and protein–protein
interactions. Several papers describe the roles of ROS, redox signalling
and antioxidants in the plant stress signalling network, and in the
interactions with phytohormone signalling cascades that govern plant
responses to biotic and abiotic stresses (Ahammed et al., 2017;
Karpinska et al., 2017; Song et al., 2017; Xia et al., 2017; Zhou et al.,
2017). Cell proliferation and fate can also be regulated by control of
FIGURE 1 Pollinators such as bees are very attracted to legumes
because of the high nutrient content of their pollen and nectar.
Bumblebee feeding on soybean (variety Sultana) in a field experiment
in 2015 in Müncheberg, Germany
FIGURE 2 Xerohalophytes growing in soil impacted by severe
salinity and drought
FIGURE 3 Cultivation of salt‐tolerant crops such as Agave sp.on
marginal lands in India
878 EDITORIAL
oxygen availability. The role of physiological hypoxia in the control of
the bud burst is also discussed (Meitha et al., 2017).
Two manuscripts (Dixit et al., 2017; Gupta et al., 2017) describe
the development of strategies for improving crop resiliency against
multiple stresses for producing better yields with limited agronomic
inputs. In particular, the paper by Gupta et al. (2017) reports the
generation of rice plants with improved adaptation towards multiple
abiotic and biotic stresses with reduced yield penalty through manip-
ulation of the glyoxalase pathway. Methylglyoxal (MG) is a cytotoxic
metabolite that is accumulated as a consequence of many abiotic
and biotic stresses. MG accumulation may therefore be a linking factor
in plant responses to diverse stresses. This paper reports that genetic
manipulation of the two‐step glyoxalase pathway that removes MG
led to improved tolerance of rice to multiple abiotic and biotic
stresses. The enhanced stress tolerance observed in the glyoxalase‐
overexpressing rice plants was attributed to improved MG detoxifica-
tion, reduced levels of ROS accumulation, and better protection of
photosynthesis (Gupta et al., 2017). Hence, prevention of MG accu-
mulation is a promising strategy to develop improved crops with
enhanced tolerance to a range of abiotic and biotic stresses.
The study described in the paper by Dixit et al. (2017) highlights
the role of novel stress‐associated proteins (SAPs) in providing toler-
ance to the multiple abiotic stresses experienced by plants. The
Arabidopsis and rice genomes were found to contain 14 and 18 genes
encoding SAP‐related proteins, respectively. Most of the SAP genes in
plants are differentially regulated in response to multiple environmen-
tal stresses such as low temperatures (LTs), salinity, drought, heavy
metals, wounding, and submergence. Transgenic Arabidopsis lines
overexpressing AtSAP13 were found to show improved tolerance to
drought and salt stresses, and also toxic metals including arsenic (As),
cadmium (Cd), and zinc (Zn) (Dixit et al., 2017). The mode of action of
AtSAP13 proteins and their roles in tolerance to multiple abiotic
stresses was analysed using DNA‐protein interaction assays (Dixit
et al., 2017). Several transcription factors related to abiotic stress toler-
ance were shown to bind to the AtSAP13 promoter. AtSAP13 and its
homologs could therefore be used to develop climate resilient crops.
The role of abscisic acid‐responsive transcription factors (ABFs) in
the regulation of drought tolerance in cotton is described in detail in
the paper by Kerr et al. (2017). A functional analysis of two genes that
encode representative ABFs from Arabidopsis and cotton was under-
taken. Expression of the Arabidopsis or cotton ABFs in transgenic
cotton plants led to increased drought stress tolerance both under
controlled greenhouse conditions and in the field (Kerr et al., 2017).
Some of the transgenic lines analysed were better able to maintain
yields during dry conditions in the field than the wild‐type or
nonexpressing controls. Hence, the increased expression of ABFs
could provide a realistic mechanism to improve the performance of
cotton in the field and develop more drought tolerant cotton varieties
(Kerr et al., 2017).
Enhanced rice grain yields, achieved through manipulation of
cytokinin homeostasis in the inflorescence meristem, are reported in
the paper by Joshi et al. (2017). Cytokinin is degraded by the enzyme
cytokinin oxidase (CKX) in the rice inflorescence. Knockdown of the
inflorescence meristem‐specific CKX, OsCKX2, resulted in elevated
cellular cytokinin levels, which in turn, lead to enhanced panicle
branching with more grains filled per plant under unstressed and salin-
ity stress conditions (Joshi et al., 2017). These findings shed new light
on the complex crosstalk between cytokinin metabolism, abiotic stress
tolerance, and grain yield.
Increasing soil contamination as a result of industrial activities and
agricultural practices, such as use of recycled wastewater and under-
ground water contaminated with heavy metals such as arsenic
(Figure 4), has not only caused a decline in crop productivity but has
also led to serious food safety concerns. Phytoremediation approaches
are therefore crucial in the removal of toxic pollutants from soil and
water so that crop production can be increased on (nonarable) contam-
inated soils. This topic is described in a comprehensive review by Fasani
et al. (2017), which describes the problems associated with heavy
metals toxicity in soil, as well as the potential of genetic engineering
approaches to improve plant phytoremediation capacity in contami-
nated soils. The mechanisms that plants employ for uptake, transloca-
tion, detoxification, and accumulation of toxic metals are highlighted
in this review, which also provides a comprehensive list of the recent
studies undertaken in this field (Fasani et al., 2017). The use of
phytoremediation to improve contaminated soils and/or water is
proposed as a cost‐effective and environmental friendly “green‐clean”
technology.
1.2 |Genomics and proteomics approaches to
improve salt tolerance
Salinity is an ever‐increasing menace to agriculture worldwide. This is
particularly important for the cultivation of salt‐sensitive crops such as
rice and wheat. Rice is the second largest crop in the world and is
planted on about one tenth of the earth's arable land and is the single
largest source of food for half of humanity (FAO, 2015). Of the 130
million hectares of land used for rice cultivation, approximately 30%
contain levels of salt high enough to affect rice yield (Vinocur &
Altman, 2005; Wang, Vinocur, & Altman, 2003). The degree of suscep-
tibility to salinity varies widely between rice cultivars, pointing to
extensive genetic diversity that can be exploited to identify genes
and their corresponding proteins that are important for rice salt toler-
ance. To develop crops tolerant to salinity, it is essential to understand
FIGURE 4 Field trials of rice germplasms grown on arsenic
contaminated sites in West Bengal as a collaborative research project
of CSIR‐NBRI, Lucknow and RRS, Chinsurah, West Bengal, India.
EDITORIAL 879
the underlying physiological, molecular, and biochemical mechanisms
and identify related genes and gene networks. Patishtan et al. (2017)
report the results of a genome‐wide association studies of salt‐related
traits in 306 rice cultivars. An important region on chromosome 8 was
identified that contains a number of genes related to the
ubiquitination pathway (Patishtan et al., 2017). The process of protein
degradation is therefore proposed as a major target for improving salt
tolerance in rice. Several hundred nonsynonymous single nucleotide
polymorphisms were found in coding regions, specific genomic regions
with increased numbers of nonsynonymous single nucleotide poly-
morphisms were identified.
Two rice genotypes (the salt‐sensitive IR64 and the salt tolerant
Pokkali) with contrasting responses to salinity stress were used to
investigate the temporal differences in proteome profiles in the study
reported by Lakra et al. (2017). This paper not only demonstrates the
usefulness of the proteomics (2D‐DIGE: two‐dimensional differential
in‐gel electrophoresis) approaches to unravel the proteins involved in
salt stress tolerance in rice genotypes but also highlights the finding
that tolerant genotypes were “ready in anticipation”of stress, that is,
the stress responsive machinery remained active and responsive to
the stress signals (Lakra et al., 2017). The proteins identified in these
studies will be helpful in improving salinity tolerance in crop plants.
Genetic variations in salt tolerance were also reported in the paper
by Oyiga et al. (2017), which reports a comprehensive evaluation
and identification of quantitative trait loci conferring salt tolerance in
150 winter wheat cultivars, using a genome‐wide association study
approach. A large number of SNPs were reported in 37 quantitative
trait loci associated with the salt tolerance traits. Candidate genes
linked to these polymorphisms were identified and results confirmed
by transcriptomics and qRT‐PCR on samples harvested from plants
grown under salt stress and control conditions (Oyiga et al., 2017).
The polymorphisms identified in these two papers have biological rel-
evance that can be exploited in future breeding programs directed at
enhancing salt tolerance in wheat and rice.
The flooding of paddy fields is a common practice that could
adversely affect global rice production because complete submergence
can lead to severe damage and death of rice seedlings. Hence, the anal-
ysis of the role of gas films on leaves as a tolerance mechanisms
presented in the paper by Herzog et al. (2017) has relevance for rice
crop survival. The gas films on leaves of rice plants submerged in saline
water were shown to delay the entry of salt. Moreover, the natural loss
or removal of the leaf gas films resulted in a severe decline in photosyn-
thesis and the growth of the rice plants (Herzog et al., 2017).
1.3 |Adaptation of extreme temperature stress
Exposure to extreme temperatures (chilling, freezing, or HT) causes
detrimental effects on plant productivity and crop yields. The semiarid
regions of the world are particularly vulnerable to the weather vari-
ability associated with climate change (Arab Water Council, 2009).
Simulation studies have predicted extreme hot summers will occur
twice a decade in the future in contrast to twice a century during
2000s (Christidis, Jones, & Scott, 2014). Russia recorded the worst
ever heatwave in three decades in 2012 leading to about 55,000 casu-
alties (Russo et al., 2014). Australia recorded doubling of the annual
number of hot days over the past 50–60 years with mean temperature
increase by 0.9 °C (Deo, McAlpine, Syktus, McGowan, & Phinn, 2007).
Warming over the Indian subcontinent (both land and ocean) has been
recorded over first decade of this century (Roxy et al., 2015), and
recent studies have warned the increased occurrences of heatwaves
over the land (Rohini, Rajeevan, & Srivastava, 2016). Temperatures
are projected to rise faster in Africa than in the rest of the world, with
increases exceeding 2 °C by mid‐21st century and 4 °C by the end of
21st century (Niang et al., 2014).
A mechanistic understanding of plant responses to HT, particu-
larly when the stress is imposed at flowering, is crucial for the devel-
opment of stress tolerant genotypes because plant reproductive
organs are very sensitive to HT stress, (Farooq, Bramley, Palta, &
Siddique, 2011; Prasad, Bheemanahalli, & Jagadish, 2017). HT reduce
pollen viability and shorten the grain‐filling period, temperature
increases of 3–4 °C are likely to cause crop yields to fall by 15–35%
in Africa and Asia and by 25–35% in the Middle East (Ortiz et al.,
2008). Pearl millet (Pennisetum glaucum) has a higher HT tolerance
than many other cereals and is hence considered to be an important
climate resilient crop. Hence, like sorghum (Sorghum biclor), pearl millet
is an important cereal crop in the agriculture of arid and semiarid
regions. The impacts of HT stress in pearl millet are reported in the
paper by Djanaguiraman, Perumal, Ciampitti, et al. (2017), who identi-
fied sensitive stages and determined parameters such as temperature
thresholds, genetic variability, and the fertility of pollen and the pistil.
Exposure to HT stress was found to decrease pollen germination and
seed yield per panicle (Djanaguiraman, Perumal, Ciampitti, et al.,
2017), the periods of gametogenesis and anthesis being the most
sensitive to HT stress in terms of effects on seed yield. Negative
impacts of HT stress on the fertility of both pollen and pistil tissues
were observed, the pistil being more sensitive than pollen
(Djanaguiraman, Perumal, Ciampitti, et al., 2017). The screening of
pearl millet germplasm and identification of HT tolerant lines in this
paper will be extremely useful in future breeding programs designed
to develop parental lines or hybrids with HT tolerance.
Understanding of mechanisms that afford tolerance will assist in
the development of HT stress tolerant lines and hybrids. Similarly,
deployment and adoption of HT tolerant genotypes and/or hybrids
will increase the resilience of millet‐based cropping systems to future
climate changes. Both the pollen and pistil functions were found to
decrease in response to HT stress in grain sorghum in the study
reported by Djanaguiraman, Perumal, Jagadish, et al. (2017). In this
case, an analysis of direct and reciprocal crosses showed that sorghum
pollen was more sensitive to HT stress than the pistil, with greater
decreases in seed‐set (Djanaguiraman, Perumal, Jagadish, et al.,
2017). Loss of sorghum gamete functions under HT stress were asso-
ciated with changes in anatomy, and phospholipid composition and
level of saturation, as well as ROS levels and antioxidant enzyme
activities.
Like HT, LT stresses such as chilling and freezing also severely
impair seedling survival and lower crop yields worldwide. Several stud-
ies in this volume provide new insights into the mechanisms by which
plants perceive cold stress and how they transduce the LT signal to
activate adaptive responses (Mantri, Patade, Penna, Ford, & Pang,
2012). For example, the in planta functions of an ice‐binding protein
880 EDITORIAL
and ice recrystallization inhibition proteins, which play important roles
in freezing tolerance via antinucleating activities that inhibit nucleation
and formation of ice crystals were reported in the model grass
Brachypodium distachyon (Bredow et al., 2017). Frost damage to
flower buds is a particularly important stress for perennial crops, such
as fruit trees, causing severe economic losses. The importance of frost
damage at the developmental stage to walnut trees was highlighted
using dynamic simulation modelling of temperature and photoperiod
interactions (Charrier et al., 2017). Frost hardiness monitoring of
three walnut genotypes at low and high elevation locations over
5 years revealed contrasting phenologies and maximum hardiness.
Frost damage was shown to be controlled primality by frost exposure
and not the vulnerability of the walnut genotypes to frost damage
during the dormant periods (Charrier et al., 2017). Such studies
emphasize the importance of the mechanisms of perception of frost
signals in order to minimize the damage. Phenolic compounds such
as anthocyanins have been implicated in LT tolerance. Allelic diversity
and the evolutionary significance of gene duplication on anthocyanin
metabolism is reported in the paper by D'Amelia et al. (2017). This
study highlights the role of the R2R3 MYB transcription factor called
AN2, and its paralog AN1, in cold tolerant and cold susceptible potato
(Solanum tuberosum) varieties. The duplication of MYB genes appears
to have resulted in divergent functions, with AN1 specializing in
anthocyanin production whereas AN2 serves to activate cold stress
responses, inducing the synthesis of hydroxycinnamic acid derivatives
(D'Amelia et al., 2017).
1.4 |Phytohormones signalling and stress tolerance
in plants
Seasonal shifts in temperature induced by climate change are likely to
affect seed germination and increase the risk of crop failure, particu-
larly in economically important cereals such as wheat. Understanding
the temperature‐dependent mechanisms that influence seed germina-
tion is important in considerations of the resilience of wheat to chang-
ing environmental conditions. The molecular mechanisms underlying
LT‐regulation of abscisic acid (ABA) and gibbrelic acid (GA) metabolism
and signalling during wheat seed germination are reported in the paper
by Izydorczyk et al. (2017). LT modulation of the spatiotemporal
balance between ABA and GA levels and tissue sensitivity was
reported to occur via altered expression of genes involved in the
metabolic and signalling pathways of these phytohormones
(Izydorczyk et al., 2017). Like ABA and GA, brassinosteroids (BR) play
important roles in developmental processes as well as abiotic and biotic
stresses tolerance (Vriet, Russinova, & Reuzeau, 2012; Zhou et al.,
2014). The BR‐mediated regulation of chilling stress in tomato plants
was studied in the paper by Xia et al. (2017). BR is shown to positively
regulate chilling tolerance through a signalling cascade involving
glutaredoxin genes and the redox status of 2‐Cys peroxiredoxin, as well
as antioxidant enzymes activities (Xia et al., 2017). The BR‐induced
increases in antioxidant capacity that underpin enhanced chilling toler-
ance were found to be largely dependent on the activation of RESPIRA-
TORY BURST OXIDASE HOMOLOG and associated increases in
apoplastic ROS. Direct evidence of a crosstalk between BR and ROS
in the resistance of tomato to root‐knot nematodes is reported in the
paper by Song et al. (2017). Parasitic nematodes cause more than
$150 billion losses annually to susceptible crops worldwide (Hassan,
Pham, Shi, & Zheng, 2013). BR were shown to be positive regulators
acting to prevent infestation by root‐knot nematodes via RESPIRA-
TORY BURST OXIDASE HOMOLOG‐dependent increases in
mitogen‐activated protein kinases (Song et al., 2017).
1.5 |Oxidative signalling, photosynthesis and biotic
stress responses
ROS have multifaceted roles in plant biology. Despite the compelling
evidence that ROS mainly act as beneficial signalling agents that pro-
tect plants against stress, the concept that oxidative damage is a major
cause of stress‐induced loss of cellular functions remains in the litera-
ture (Foyer, Ruban, & Noctor, 2017). This is particularly evident in the
field of photosynthesis where the idea persists that light‐induced
damage to photosystem (PS)II causes photoinhibition requiring subse-
quent repair of the PSII D1 protein (Foyer et al., 2017). However, the
interplay between photodamage and photoprotection in PSII is shown
to be much more complex in the paper by Townsend et al. (2017).
Light‐induced photoinhibition is prevented by thermal energy dissipa-
tion processes in the thylakoid membrane that are together called
nonphotochemical quenching (NPQ). Using a new pulse amplitude
modulation fluorescence methodology, the relative contributions of
NPQ and D1 repair to photoprotection were determined under short
periods of illumination using photoinhibitors and mutant Arabidopsis
thaliana lines. These studies show that NPQ makes a much greater
contribution to PSII yield than D1 repair under short periods of illumi-
nation (Townsend et al., 2017).
ROS accumulation is controlled by a complex antioxidant scav-
enging system that includes enzymes such as superoxide dismutase,
ascorbate peroxidase, catalase, glutathione peroxidase, glutathione
reductase, and peroxiredoxins (Foyer & Shigeoka, 2011). However,
enzymes that are considered to play important antioxidative roles
such as peroxidases can also promote ROS production or ROS‐depen-
dent processes and different ROS forms (such as superoxide and
H
2
O
2
) may antagonize each other in terms of the regulation of gene
expression and low molecular weight antioxidants such as glutathione
may play an integral role in transmitting oxidative signals as well as
controlling ROS accumulation (Foyer et al., 2017). Photosynthesis is
the major source of ROS in plants. H
2
O
2
is generated in chloroplasts
via the action of superoxide dismutase during photosynthesis, and this
oxidant is also produced in the peroxisomes during photorespiration
(Foyer & Noctor, 2005). ROS production, signalling, and removal by
the antioxidant systems associated with photosynthesis provide flexi-
bility and control in the management of high light and other stresses
(Foyer et al., 2017). For example, using transgenic tobacco lines with
low and high ascorbate oxidase activity, Karpinska et al. (2017)
demonstrate how the redox state of the apoplast influences the
acclimation of photosynthesis and leaf metabolism to the changing
irradiance. High light‐dependent changes in photosynthesis rates were
significantly higher in high‐light grown leaves when the apoplast was
less oxidized, demonstrating that the redox state of the apoplast influ-
ences the extent of susceptibility of photosynthesis to high light‐
induced inhibition (Karpinska et al., 2017).
EDITORIAL 881
Stress‐induced oxidation of the cellular environment leads to
posttranslational modifications in protein structure and function that
provide a high degree of plasticity and control in response to environ-
mental stimuli. The influence of oxidative stress on two poorly charac-
terized plant posttranslational modifications, protein succinylation and
acetylation, is reported in the paper of Zhou et al. (2017). Using a pro-
teomics approach to study the oxidative stress‐induced interactions
between the succinyl‐and acetyl‐proteomes, these authors provide
evidence of the presence of H
2
O
2
‐triggered interactions between
the lysine succinylome and acetylome in rice leaves (Zhou et al.,
2017). Large numbers of acetylated and succinylated proteins were
identified in rice leaves. However, exposure to oxidative stress did
not cause large global changes in the rice acetylome or succinylome
profiles but rather led to modifications on a specific subset of the
identified sites. Moreover, succinylation exerted a strong influence
on the activities of catalase and glutathione S‐transferase 6 recombi-
nant proteins (Zhou et al., 2017).
A role for photorespiration in activating tomato leaf defenses
against Pseudomonas syringae was reported in the paper by
Ahammed et al. (2017). Climate change‐associated increase in atmo-
spheric CO
2
levels will shift the balance between photosynthetic
carbon assimilation and photorespiration in C3 plants (Walker,
VanLooke, Bernacchi, & Ort, 2016). Evidence is presented showing
that photorespiration contributes to the basal defense against
P.syringae via glycolate‐oxidase‐derived H
2
O
2
production and hence
climate changes associated decreases in photorespiration may impair
such defense response (Ahammed et al., 2017). This report supports
the concept that biotic defense pathways are promoted by photores-
piration, which is inhibited at high CO
2
. However, apparently contra-
dictory observations show that growth under elevated CO
2
can
induce salicylic acid‐dependent defenses and thus increase plant
resistance to pathogens (Noctor & Mhamdi, 2017). Moreover, ele-
vated atmospheric CO
2
concentrations were shown to protect sweet
cherry plants from the damaging effects of waterlogging (Pérez‐
Jiménez et al., 2017). Waterlogging often leads to hypoxia and
decreases plant survival via inhibition of processes such as photosyn-
thesis. However, high CO
2
was able to offset some of negative effects
of hypoxia in sweet cherry (Pérez‐Jiménez et al. 2017). Resolution of
such apparently contradictory observations requires a much greater
understanding of climate change‐related changes in the relationships
between primary metabolism, inducible defenses, and resistance to
abiotic and biotic stresses (Noctor & Mhamdi, 2017).
The developmental control of hypoxia during bud burst in grape-
vine (Vitis vinifera L.) is reported in the paper by Meitha et al. (2017).
The uniform control of bud burst is important in woody perennial spe-
cies because it helps to synchronizing flowering, fruit set, and harvest.
Evidence is presented in support of a role for oxygen‐dependent
signalling in the coordination of the resumption of transcriptional
and metabolic processes during bud burst in grapevine after a period
of dormancy (Meitha et al., 2017). The release from physiological
hypoxia and associated transcript profiles are documented over the
first 24 hr period during the resumption of growth in postdormant
buds. Evidence is provided in support of oxygen‐dependent signalling
via the grapevine VII ethylene response factors during the transition
from quiescence to bud burst (Meitha et al., 2017).
These studies presented in the different manuscripts that com-
prise this special issue not only increase current knowledge of the
genes, processes, and underlying mechanisms of stress tolerance/
resistance and associated crop resilience but they also identify poten-
tial new strategies for developing climate‐resilient crops that will have
enhanced and sustained productivity traits that will help to ensure
global food security. These papers also contribute essential new ideas
that are required to transform food production and so address the
SDGs, with all their complex interactions and trade‐offs.
ACKNOWLEDGMENTS
We thank the Worldwide University Network (WUN) for financial
support for the Climate Resiliency Open Partnership for Food Security
(CROP‐FS) consortium. We thank Mrs. Gunhild Rosner, ZALF,
Germany, for Figure 1, Prof. Ashwani Pareek, School of Life Sciences,
Jawaharlal Nehru University, New Delhi, India, for Figures 2 and 3, and
Dr. R. D. Tripathi, National Botanical Research Institute Lucknow,
India for Figure 4.
ORCID
Om Parkash Dhankher http://orcid.org/0000-0003-0737-6783
Christine H. Foyer http://orcid.org/0000-0001-5989-6989
KEYWORDS
abiotic stresses, climate change, food safety, food security, oxidative
stress
Om Parkash Dhankher
1
Christine H. Foyer
2
1
Stockbridge School of Agriculture, University of Massachusetts Amherst
MA, Amherst, MA 01003, USA
2
Centre for Plant Sciences, School of Biology, Faculty of Biological
Sciences, University of Leeds, Leeds LS2 9JT, UK
Correspondence
Christine H. Foyer, Centre for Plant Sciences, School of Biology, Faculty of
Biological Sciences, University of Leeds, Leeds LS2 9JT, UK.
Email: c.foyer@leeds.ac.uk
REFERENCES
Ahammed, G. J., Li, X., Zhang, G., Zhang, H., Shi, J., Pan, C., …Shi, K. (2017).
Tomato photorespiratory glycolate oxidase‐derived H
2
O
2
production
contributes to basal defense against Pseudomonas syringae.Plant, Cell
& Environment,41. 1126–1138.
Arab Water Council (2009). Vulnerability of arid and semi‐arid regions to
climate change—Impacts and adaptive strategies. Perspectives on Water
and Climate Change Adaptation,9,1–16.
Bredow, M., Tomalty, H. E., Smith, L., & Walker, V. K. (2017). Ice and anti‐
nucleating activities of an ice‐binding protein from the annual grass,
Brachypodium distachyon.Plant, Cell & Environment,41. 983–992.
Charrier, G., Chuine, I., Bonhomme, M. & Améglio, T. (2017). Assessing
frost damages using dynamic models in walnut trees: Exposure rather
than vulnerability controls frost risks. Plant, Cell & Environment,41,
1008–1021.
Christidis, N., Jones, G. S., & Scott, P. A. (2014). Dramatically increasing
chance of extremely hot summers since the 2003 European heatwave.
Nature Climate Change,5,46–50.
882 EDITORIAL
D'Amelia, V., Aversano, R., Ruggiero, A., Batelli, G., Appelhagen, I., Dinacci,
C., …Carputo, D. (2017). Subfunctionalization of duplicate MYB genes
in Solanum commersonii generated the cold‐induced ScAN2 and the
anthocyanin regulator ScAN1. Plant, Cell & Environment,41. 1038–1051.
Deo R.C., McAlpine C.A., Syktus J., McGowan H.A. & Phinn S. (2007) On
Australian teat Waves: Time series analysis of extreme temperature
events in Australia, 1950–2005. Modsim 2007: International Congress
on Modelling and Simulation. 626–635.
Dixit, A., Tomar, P., Vaine, E., Abdullah, H., Hazen, S., & Dhankher, O. P.
(2017). A stress‐associated protein, AtSAP13, from Arabidopsis thaliana
provides tolerance to multiple abiotic stresses. Plant, Cell &
Environment,41. 1171–1185.
Djanaguiraman, M., Perumal, R., Ciampitti, I. A., Gupta, S. K., & Prasad, P. V.
V. (2017). Quantifying pearl millet response to high temperature stress:
thresholds, sensitive stages, genetic variability and relative sensitivity
of pollen and pistil. Plant, Cell & Environment,41. 993–1007.
Djanaguiraman, M., Perumal, R., Jagadish, S. V. K., Ciampitti, I. A., Welti, R.,
& Prasad, P. V. V. (2017). Sensitivity of sorghum pollen and pistil to
high‐temperature stress. Plant, Cell & Environment,41. 1065–1082.
Farooq, M., Bramley, H., Palta, J. A., & Siddique, K. H. M. (2011). Heat
stress in wheat during reproductive and grain‐filling phases. Critical
Reviews in Plant Sciences,30,1–17.
Fasani, E., Manara, A., Martini, F., Furini, A., & DalCorso, G. (2017). The
potential of genetic engineering of plants for the remediation of soils con-
taminated with heavy metals. Plant, Cell & Environment,41.1201–1232.
Food and Agriculture Organization of the United Nations (2015).
FAOSTAT. Rome: Food and Agriculture Organization of the United
Nations.
Food and Agriculture Organization of the United Nations (2017). The future
of food and agriculture—Trends and challenges. Rome: Food and
Agriculture Organization of the United Nations.
Foyer, C. H., & Noctor, G. (2005). Redox homeostasis and antioxidant sig-
nalling: A metabolic interface between stress perception and
physiological responses. Plant Cell,17, 1866–1875.
Foyer, C. H., Ruban, A. V., & Noctor, G. (2017). Viewing oxidative stress
through the lens of oxidative signalling rather than damage. Biochemical
Journal,474, 877–883.
Foyer, C. H., & Shigeoka, S. (2011). Understanding oxidative stress and
antioxidant functions to enhance photosynthesis. Plant Physiology,
155,93–100.
Gupta, B., Sahoo, K., Ghosh, A., Tripathi, A., Anwar, K., Das, P., …Pareek, S.
(2017). Manipulation of glyoxalase pathway confers tolerance to multi-
ple stresses in rice. Plant, Cell & Environment,41, 1186–1200.
Hassan, A. W., Pham, T. H., Shi, H., & Zheng, J. (2013). Nematodes threats
to global food security. Acta Agriculturae Scandinavica, Section B‐Soil &
Plant Science,63, 420–425.
Herzog, M., Konnerup, D., Pedersen, O., Winkel, A., & Colmer, T. (2017).
Leaf gas films contribute to rice (Oryza sativa) submergence tolerance
during saline floods. Plant, Cell & Environment,41, 885–897.
Izydorczyk, C., Nguyen, T.‐N., Jo, S. H., Son, S. H. T., Anh, P., & Ayele, B.
(2017). Spatiotemporal modulation of abscisic acid and gibberellin
metabolism and signalling mediates the effect of suboptimal and
supraoptimal temperatures on seed germination in wheat (Triticum
aestivum L.). Plant, Cell & Environment,41, 1022–1037.
Joshi, R., Sahoo, K., Tripathi, A., Kumar, R., Gupta, B., Pareek, A., & Pareek,
S. (2017). Knockdown of an inflorescence meristem‐specific cytokinin
oxidase—OsCKX2 in rice reduces yield penalty under salinity stress
condition. Plant, Cell & Environment,41, 936–946.
Karpinska, B., Zhang, K., Rasool, B., Pastok, D., Morris, J., Verrall, S., …
Foyer, C. H. (2017). The redox state of the apoplast influences the
acclimation of photosynthesis and leaf metabolism to changing irradi-
ance. Plant, Cell & Environment,41, 1083–1097.
Kathuria, H., Giri, J., Tyagi, H., & Tyagi, A. K. (2007). Advances in transgenic
rice biotechnology. Critical Reviews in Plant Sciences,26,65–103.
Kerr, T. C., Abdel‐Mageed, H., Aleman, L., Lee, J., Payton, P., Cryer, D., &
Allen, R. D. (2017). Ectopic expression of two AREB/ABF orthologs
increases drought tolerance in cotton (Gossypium hirsutum). Plant, Cell
& Environment,41, 898–907.
Lakra, N., Kaur, C., Anwar, K., Pareek, S., & Pareek, A. (2017). Proteomics of
contrasting rice genotypes: Identification of potential targets for raising
crops for saline environment. Plant, Cell & Environment,41, 947–969.
Long, S. P., Marshall‐Colon, A., & Zhu, X.‐G. (2015). Meeting the global
food demand of the future by engineering crop photosynthesis and
yield potential. Cell,161,56–66.
Mantri, N., Patade, V., Penna, S., Ford, R., & Pang, E. (2012). Abiotic stress
responses in plants: Present and future. In P. Ahmad, & M. N. V. Prasad
(Eds.), Abiotic stress responses in plants: Metabolism, productivity and
sustainability (pp. 1–19). New York, NY: Springer New York.
Meitha, K., Agudelo‐Romero, P., Signorelli, S., Gibbs, D., Considine, J., Foyer,
C. H., & Considine, M. (2017). Developmental control of hypoxia during
bud burst in grapevine. Plant, Cell & Environment,41, 1154–1170.
Niang, I., Ruppel, O. C., Abdrabo, M. A., Essel, A., Lennard, C., Padgham, J.,
& Leary, N. A. (2014). Africa in climate change: Impacts, adaptation, and
vulnerability. Part B: Regional aspects. In V. R. Barros, C. B. Field, D. J.
Dokken, M. D. Mastrandrea, K. J. Mach, T. E. Bilir, et al. (Eds.), Contribu-
tion of working group II to the fifth assessment report of the
intergovernmental panel on climate change (pp. 1199–1265). Cambridge,
United Kingdom and New York, NY: Cambridge University Press.
Noctor, G., & Mhamdi, A. (2017). Climate change, CO
2
, and defense: The
metabolic, redox, and signaling perspectives. Trends in Plant Science,
22, 857–870.
Nüsslein, K., & Dhankher, O. P. (2016). Project management: Food security
needs social‐science input. Nature,535,37–37.
Ortiz, R., Braun, H. J., Crossa, J., Crouch, J. H., Davenport, G., Dixon, J., …
Iwanaga, M. (2008). Wheat genetic resources enhancement by the
International Maize and Wheat Improvement Center (CIMMYT).
Genetic Resources and Crop Evolution,55, 1095–1140.
Oyiga, B., Sharma, R., Baum, M., Ogbonnaya, F., Léon, J., & Ballvora, A.
(2017). Allelic variations and differential expressions detected at QTL
loci for salt stress tolerance in wheat. Plant, Cell & Environment,41,
919–935.
Patishtan, J., Hartley, T., Fonseca de Carvalho, R., & Maathuis, F. J. M.
(2017). Genome wide association studies to identify rice salt tolerance
markers. Plant, Cell & Environment,41, 970–982.
Pérez‐Jiménez, M., Hernández‐Munuera, M., Piñero, M. C., López‐Ortega,
G., & del Amor, F. (2017). Are commercial sweet cherry rootstocks
adapted to climate change? Short‐term waterlogging and CO
2
effects
on sweet cherry cv. ‘Burlat’.Plant, Cell & Environment,41, 908–918.
Prasad, P. V. V., Bheemanahalli, R., & Jagadish, S. V. K. (2017). Field crops
and the fear of heat stress‐Opportunities, challenges and future direc-
tions. Field Crops Research,200, 114–121.
Ray, D. K., Mueller, N. D., West, P. C., & Foley, J. A. (2013). Yield trends are
insufficient to double global crop production by 2050. PLoS one,8.
e66428
Reckling, M., Doring, T. F., Berkvist, G., Chmielewski, F.‐M., Stoddard, F. L.,
Watson, C. A., …Bachinger, J. (2018). Grain legume yield instability has
increased over 60 years in long‐term field experiments as measured by
a scale‐adjusted coefficient of variation. Aspects of Applied Biology,138,
15–20.
Rohini, P., Rajeevan, M., & Srivastava, A. K. (2016). On the variability and
increasing trends of heat waves over India. Science Reports,6, 26153.
Roxy, M. K., Kapoor, R., Terray, P., Murtugudde, R., Ashok, K., & Goswami,
B. N. (2015). Drying of Indian subcontinent by rapid Indian Ocean
warming and a weakening land‐sea thermal gradient. Nature Communi-
cations,6, 7423.
Russo, S., Dosio, A., Graversen, R. G., Sillmann, J., Carrao, H., Dunbar, M. B.,
…Vogt, J. V. (2014). Magnitude of extreme heat waves in present cli-
mate and their projection in a warming world. Journal of Geophysical
Research: Atmospheres,119, 12500–12512.
EDITORIAL 883
Song, L.‐X., Xu, X.‐C., Wang, F.‐N., Wang, Y., Xia, X. J., Shi, K., …Yu, J. Q.
(2017). Brassinosteroids act as a positive regulator for resistance
against root knot nematode involving RESPIRATORY BURST OXIDASE
HOMOLOG‐dependent activation of MAPKs in tomato. Plant, Cell &
Environment,41, 1113–1125.
Townsend, A., Ware, M., & Ruban, A. (2017). Dynamic interplay between
photodamage and photoprotection in photosystem II. Plant, Cell &
Environment,41, 1098–1112.
Vinocur, B., & Altman, A. (2005). Recent advances in engineering plant
tolerance to abiotic stress: Achievements and limitations. Current Opin-
ion in Plant Science,16,1–10.
Vriet, C., Russinova, E., & Reuzeau, C. (2012). Boosting crop yields with
plant steroids. The Plant Cell,24, 842–857.
Walker, B.J., VanLoocke, A., Bernacchi, C.J., &, Ort, D.R. (2016). The costs
of photorespiration to food production now and in the future. Annual
Review of Plant Biology,67, 107–129.
Wang, W., Vinocur, B., & Altman, A. (2003). Plant response to drought,
salinity, and extreme temperatures: Towards genetic engineering for
stress tolerance. Planta,218,1–14.
Xia, X.‐J., Fang, P.‐P., Guo, X., Qian, X.‐J., Zhou, J., Shi, K., …Yu, J.‐Q.
(2017). Brassinosteroid‐mediated apoplastic H
2
O
2
‐glutaredoxin 12/14
cascade regulates antioxidant capacity in response to chilling in
tomato. Plant, Cell & Environment,41, 1052–1064.
Zhou, H., Finkemeier, I., Guan, W., Tossounian, M., Wei, B., Young, D., …
Foyer, C. H. (2017). Oxidative stress‐triggered interactions between
the succinyl‐and acetyl‐proteomes of rice leaves. Plant, Cell &
Environment,41, 1139–1153.
Zhou, J., Xia, X. J., Zhou, Y. H., Shi, K., Chen, Z., & Yu, J. Q. (2014). RBOH1‐
dependent H
2
O
2
production and subsequent activation of MPK1/2
play an important role in acclimation‐induced cross‐tolerance in
tomato. Journal of Experimental Botany,65, 595–607.
884 EDITORIAL