Influence of arbuscular mycorrhizal fungi on the functional mechanisms associated with drought tolerance in carob (Ceratonia siliqua L.)

Abstract

Key message
Arbuscular mycorrhizal symbiosis strengthened the mechanisms developed by carob to withstand drought stress, including improved water relations, increased cell wall rigidity and osmolytes accumulation, and enhanced oxidative stress alleviation.

Abstract
The present investigation was carried out to provide more insight into the influence of arbuscular mycorrhizal fungi (Funneliformis mosseae, Rhizophagus fasciculatus, and Rhizophagus intraradices) on drought tolerance of carob. Non-mycorrhizal (NM) and arbuscular mycorrhizal (AM) carob plants were subjected to two watering regimes, 75% of field capacity (well water) or 25% of field capacity (water stress). Obtained results showed that stressed AM plants exhibited increased performance in terms of growth and biomass production, water and nutrient acquisition, and oxidative stress alleviation compared to NM plants. In fact, under limited water regime, AM plants maintained high stomatal conductance and high relative water content (over 94%) due to their high water and nutrient uptake efficiency. Moreover, AM plants especially those associated with F. mosseae maintained high membrane integrity (over 80%), high cell wall rigidity, and high leaf water potential and osmotic potential at full turgor and at turgor loss, while these parameters steeply decreased in NM plants. Furthermore, drought-stressed AM plants showed decreased hydrogen peroxide and malondialdehyde contents associated with increased activities of superoxide dismutase, ascorbate peroxidase, guaiacol peroxidase, and catalase compared to their relative NM plants. Thus, AMF strengthened the mechanisms involved in drought tolerance of carob by improving water relations, increasing cell wall rigidity, and enhancing oxidative stress alleviation. Funneliformis mosseae was the most effective in improving carob tolerance to drought stress.

Full text

Vol.:(0123456789)
1 3
Trees (2018) 32:87–97
DOI 10.1007/s00468-017-1613-8
ORIGINAL ARTICLE
Influence ofarbuscular mycorrhizal fungi onthefunctional
mechanisms associated withdrought tolerance incarob
(Ceratonia siliqua L.)
AbdellatifEssahibi1· LailaBenhiba1· MohamedAitBabram2· CherkiGhoulam1·
AhmedQaddoury1
Received: 7 April 2017 / Accepted: 1 September 2017 / Published online: 9 September 2017
© Springer-Verlag GmbH Germany 2017
drought-stressed AM plants showed decreased hydrogen
peroxide and malondialdehyde contents associated with
increased activities of superoxide dismutase, ascorbate per-
oxidase, guaiacol peroxidase, and catalase compared to their
relative NM plants. Thus, AMF strengthened the mecha-
nisms involved in drought tolerance of carob by improving
water relations, increasing cell wall rigidity, and enhanc-
ing oxidative stress alleviation. Funneliformis mosseae was
the most effective in improving carob tolerance to drought
stress.
Keywords Ceratonia siliqua· Arbuscular mycorrhizal
fungi· Drought stress· Water relations· Antioxidant
metabolism· Osmotic adjustment
Introduction
Carob (Ceratonia siliqua L.) tree is an important compo-
nent of the arboreal flora of the Mediterranean regions,
where it is widely cultivated for economic, environmen-
tal, and social benefits (Batlle and Tous 1997). Indeed,
seeds and pods of carob are used in food, pharmaceutical,
chemical, and cosmetic industries (Makris and Kefalas
2004; Barracosa etal. 2007; Konate 2007; Custodio etal.
2011a, b). In addition, carob tree plays a key role in the
conservation and rehabilitation of marginal areas of Med-
iterranean basin, where it plays the role of pioneer and
productive species. Carob can also be used for charcoal,
wood industry, and to prevent soil erosion (Barwick 2004;
Pérez-García 2009). Several studies reported the capacity
of carob tree to tolerate dryness and salinity and to adapt
to nutrient poor and degraded soils (Vertovec etal. 2001;
Sakcali and Ozturk 2004; Correia etal. 2010; Ozturk
etal. 2010; El-Refaey etal. 2011; El Asri etal. 2013,
Abstract
Key message Arbuscular mycorrhizal symbiosis
strengthened the mechanisms developed by carob to
withstand drought stress, including improved water rela-
tions, increased cell wall rigidity and osmolytes accumu-
lation, and enhanced oxidative stress alleviation.
Abstract The present investigation was carried out to pro-
vide more insight into the influence of arbuscular mycor-
rhizal fungi (Funneliformis mosseae, Rhizophagus fascicu-
latus, and Rhizophagus intraradices) on drought tolerance
of carob. Non-mycorrhizal (NM) and arbuscular mycorrhizal
(AM) carob plants were subjected to two watering regimes,
75% of field capacity (well water) or 25% of field capacity
(water stress). Obtained results showed that stressed AM
plants exhibited increased performance in terms of growth
and biomass production, water and nutrient acquisition, and
oxidative stress alleviation compared to NM plants. In fact,
under limited water regime, AM plants maintained high
stomatal conductance and high relative water content (over
94%) due to their high water and nutrient uptake efficiency.
Moreover, AM plants especially those associated with F.
mosseae maintained high membrane integrity (over 80%),
high cell wall rigidity, and high leaf water potential and
osmotic potential at full turgor and at turgor loss, while these
parameters steeply decreased in NM plants. Furthermore,
Communicated by P. E. Courty.
* Abdellatif Essahibi
abdellatif.essahibi@gmail.com
1 Department ofBiology, Faculty ofSciences andTechniques,
Cadi Ayyad University, Marrakesh, Morocco
2 Department ofMathematics, Faculty ofSciences
andTechniques, Cadi Ayyad University, Marrakesh,
Morocco
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