Sarah Cookson

• Doctor of Philosophy
• Researcher at French National Institute for Agriculture, Food, and Environment (INRAE)

The success of grafting in grapevine nurseries can vary significantly depending on the wood used, even if the same scion and rootstock are used, yet the underlying causes of this variation remain poorly understood. To elucidate the factors influencing grafting success, rootstock wood (Vitis berlandieri x V. rupestris cv. 110 Richter) from ten produ...

Just over 150 years ago, grape phylloxera, Daktulosphaera vitifoliae, was introduced to Europe from North America via imports of plant material. This aphid-like insect has spread rapidly to most vineyards, causing rapid and lethal decline of Vitis vinifera. What happened in the second half of the 19 th century in response to this pest has shaped th...

The success of grafting and the sustained growth of newly grafted grapevines depend on the ability of hardwood cuttings taken from parent plants to rapidly initiate new adventitious roots (ARs) and to establish a functional, well-distributed root system in the soil. There is a paucity of literature on the plasticity and diversity of grapevine root...

Rootstocks are potentially important levers of adaptation in the context of climate change. In this study, we investigated the effect of the rootstock and its genetic background on plant mineral status. The scion, the rootstock, and their interactions had a significant influence on petiole mineral content and explained the same proportion of phenot...

Rootstocks are an important means of adapting grapevine to environmental conditions whilst conserving the typical features of scion genotypes. Rootstocks not only provide tolerance to Phylloxera, but also ensure the supply of water and mineral nutrients to the scion. We take advantage of the large diversity of rootstocks used worldwide to facilitat...

Plants are able to naturally graft or inosculate their trunks, branches and roots together, this mechanism is used by humans to graft together different genotypes for a range of purposes. Grafts are considered successful if functional vascular connections between the two genotypes occur. Various techniques can evaluate xylem connections across the...

Grafting is widely used in horticulture. Shortly after grafting, callus tissues appear at the graft interface and the vascular tissues of the scion and rootstock connect. The graft interface contains a complex mix of tissues, we hypothesised that each tissue has its own metabolic response to wounding/grafting and accumulates different metabolites a...

Grapevines are grown grafted in most viticultural regions. Grapevine rootstocks are either hybrids or pure species of different American Vitis spp. (particularly V. berlandieri, V. rupestris and V. riparia), which were primarily used to provide root resistance to the insect pest Phylloxera. In addition to Phylloxera resistance, grapevine rootstocks...

Grapevines are continually wounded throughout their cultivation especially during winter pruning. Grapevines respond to wounding by occluding xylem vessels with gels or tyloses to limit pathogen attack and dehydration of the tissues (Sun et al., 2006, 2007, 2008). Although the production of xylem vessel occlusions has been studied in grapevine, to...

Grapevines are grown grafting in most viticultural regions. Grapevine rootstocks are either hybrids or pure species of different American Vitis spp. (particularly V. berlandieri, V. rupestris and V. riparia), which are primarily used to provide root resistance to the insect pest Phylloxera. In addition to Phylloxera resistance, ideally grapevine ro...

Context and purpose of the study – Grapevines are continually wounded throughout their cultivation especially during winter pruning. Grapevines respond to wounding by occluding xylem vessels with gels or tyloses to limit pathogen attack and dehydration of the tissues. Although the production of xylem vessel occlusions has been studied in grapevine,...

Context and purpose of the study – Grapevines are grown grafted in most viticultural regions. Grapevine rootstocks are either hybrids or pure species of different American Vitis spp. (particularly V. berlandieri, V. rupestris and V. riparia), which were primarily used to provide root resistance to the insect pest Phylloxera. In addition to Phylloxe...

Grafting is widely used in horticulture, shortly after grafting, callus tissues appear at the graft interface and the vascular tissues of the scion and rootstock connect. The graft interface contains a complex mix of tissues, we hypothesized that each tissue have is own metabolic response to wounding/grafting and accumulate different metabolites at...

Grafting is a traditional horticultural technique that makes use of plant wound healing mechanisms to join two different genotypes together to form one plant. In many agricultural systems, grafting with rootstocks controls the vigour of the scion and/or provides tolerance to deleterious soil conditions such as the presence of soil pests or pathogen...

Combining two different plants together through grafting is one of the oldest horticultural techniques. In order to survive, both partners must communicate via the formation of de novo connections between the scion and the rootstock. Despite the importance of grafting, the ultrastructural processes occurring at the graft interface remain elusive du...

The production of grafted grapevine plant material is a complex process with many steps running over at least one year, from grafting to final sorting in nurseries. To reach the market in France, grafted grapevines must meet three criteria by law: resistance to a manual graft union test (or thumb test), a minimum number of three roots and a woody,...

Grafting is an ancient method that has been intensively used for the clonal propagation of vegetables and woody trees. Despite its importance in agriculture the physiological and molecular mechanisms underlying phenotypic changes of plants following grafting are still poorly understood. In the present study, we analyse the populations of small RNAs...

Grafting is an important horticultural technique used for many crop species. However, some scion/rootstock combinations are considered as incompatible due to poor graft union formation and subsequently high plant mortality. The early identification of graft incompatibility could allow the selection of non-viable plants before planting and would hav...

Despite recent progress in our understanding of graft union formation, we still know little about the cellular events underlying the grafting process. This is partially due to the difficulty of reliably targeting the graft interface in electron microscopy to study its ultrastructure and three-dimensional architecture. To overcome this technological...

Despite recent progress in our understanding of the graft union formation, we still know little about the cellular events underlying the grafting process. This is partially due to the difficulty of reliably targeting the graft interface in electron microscopy to study its ultrastructure and three-dimensional architecture. To overcome this technolog...

Phosphorus is essential for plant life and plants have developed numerous strategies to maximise phosphate (Pi) acquisition and use under limited Pi supply. Here we have used reciprocal grafting to determine whether the shoot and root have different roles in regulating some of these strategies. Reciprocal grafts of two grapevine genotypes (Vitis vi...

Grafting is a technique used for millennia for vegetative propagation, especially in perennial fruit crops. This method, used on woody and herbaceous plants, can improve several agronomic characteristics, such as yield or vigor, as well as tolerance to biotic and abiotic stresses. However, some scion/rootstock combinations suffer from poor graft co...

Background: Grafting is widely used in horticulture and rootstocks are known to modify scion growth and adaptation to soil conditions. However, the role of scion genotype in regulating rootstock development and functioning has remained largely unexplored. In this study, reciprocal grafts of two grapevine genotypes were produced as well as the corr...

Grapevine canes are an abundant by-product of wine industry. The stilbene contents of Vitis vinifera cultivars have been largely studied, but little is known about the stilbene contents of wild Vitis accessions. Moreover, there have only been few studies on the quantification of other phenolic compounds in just pruned grapevine canes. In our study,...

Background: Grapevine is a crop of major economic importance, yet little is known about the regulation of shoot development in grapevine or other perennial fruits crops. Here we combine genetic and genomic tools to identify candidate genes regulating shoot development in Vitis spp. Results: An F2 population from an interspecific cross between V....

Background and aims: In most viticultural areas of the world, Vitis vinifera grapevines require grafting onto phylloxera-tolerant rootstocks of American origin. The species most commonly used in rootstock creation are Vitis berlandieri, V. riparia and V. rupestris. Rootstocks not only provide tolerance to phylloxera but also ensure the supply of wa...

Backgrounds and aims: Grapevine, Vitis vinifera, requires grafting on Phylloxera tolerant rootstocks of American origin in most viticultural areas of the world. The most commonly used species in rootstock creation are V. berlandieri, V. riparia and V. rupestris. Rootstocks not only provide tolerance to Phylloxera but assure the supply of water and...

Background: Grafting with rootstocks is essential for the culture of many perennial fruit crops and is increasing being used in the production of annual fruits and vegetables. Our previous work based on microarrays showed that transcripts encoding enzymes of both primary and secondary metabolism were differentially expressed during graft union for...

As the climate changes, genetic adaptation of crops to abiotic stresses is an increasingly important issue, especially for a perennial crops of high economic value such as grapevine. Given the numerous environments where this plant can be found, and the huge intra- and interspecific diversity, we can assume that grapevine genomes contain many aile...

Grafting has been utilized for at least the past 7000 years. However, historically grafting has been developed by growers without particular interest beyond the agronomical and ornamental effects, thus knowledge about grafting has remained largely empirical. Much of the commercial production of fruit, and increasingly vegetables, relies upon grafti...

In viticulture, grafting is used to facilitate grapevine cultivation in soils infected with phylloxera, a soil-dwelling insect pest introduced to Europe from America at the end of the 19th century. Successful grafting of plants is a complex biochemical and structural process that begins with an initial wound response, followed by callus formation a...

Crop productivity is limited by phosphorus (P) and this will probably increase in the future. Rootstocks offer a means to increase the sustainability and nutrient efficiency of agriculture. It is known that rootstocks alter petiole P concentrations in grapevine. The objective of this work was to determine which functional processes are involved in...

In grafted plants, rootstocks assure the mineral nutrition of the scion and modify its development. In this work, we show that two grapevine rootstock genotypes present different shoot branching architectures when cultivated as cuttings and that this trait is transmitted to the scion when grafted. Shoot branching plasticity in response to nitrogen...

The sections in this article are Introduction Environmental Stresses Affect Spatial and Temporal Patterns of Cell Division Rate in Plant Organs Coupling and Uncoupling of Cell Division and Tissue Expansion in Response to Environmental Conditions Environmental Stresses Cause a Blockage at the G1–S and G2–M Transitions Endoreduplication and Abio...

Key message: QTLs were identified for traits assessed on field-grown grafted grapevines. Root number and section had the largest phenotypic variance explained. Genetic control of root and aerial traits was independent. Breeding new rootstocks for perennial crops remains challenging, mainly because of the number of desirable traits which have to be...

Since the second half of the XIXth century, grapevine has been grown grafted worldwide to cope with Phylloxera. Consequently, the cultivated grapevine is a chimeric plant made from two genotypes which interact together. The result of this interaction must ensure a balanced functioning dedicated to fruit production in terms of quantity and quality....

In many fruit species, including grapevine, grafting is used to improve scion productivity and quality and to adapt the plant to environmental conditions. However, the mechanisms underlying the rootstock control of scion development are still poorly understood. The ability of rootstocks to regulate nitrogen uptake and assimilation may contribute to...

Although the benefits of using grafted transplants are now fully recognized worldwide, the need to enlighten the scientific basis of rootstock-scion interactions under variable environmental pressures remains vital for extracting grafting-mediated crop improvement. This has prompted the COST (European Cooperation in Science and Technology) Action F...

This chapter aims to review the biology of grafting and the factors influencing graft compatibility, focusing on the molecular and physiological aspects affecting graft development and success in herbaceous and woody plants. Recently, genes known to be involved in wounding/healing, vascular differentiation, programmed cell death, reactive oxygen sp...

Root system architecture (RSA) is important for rootstock adaptation to soil resource-limited environments, but our knowledge of root traits is hampered by the lack of high-throughput root phenotyping systems for perennial fruit crops such as grapevine. Numerous approaches have been developed for non-destructive observations of RSA with the support...

Background ABA-mediated processes are involved in plant responses to water deficit, especially the control of stomatal opening. However in grapevine it is not known if these processes participate in the phenotypic variation in drought adaptation existing between genotypes. To elucidate this question, the response to short-term water-deficit was ana...

Abstract In order to cope with phylloxera, most grapes worldwide must be grafted on a rootstock. Furthermore, grapevine rootstocks are an essential underground structure for the plant to face various pests and diseases and to adapt to different types of soil. This review focuses on the existing information about rootstock properties in relation...

To investigate whether the transcriptional response to carbon (C) depletion and sucrose resupply depends on the duration and severity of the C-depletion, Arabidopsis seedlings were grown in liquid culture and harvested 3, 6, 12, 24, 48 and 72 hours after removing sucrose from the medium, and 30 minutes after resupplying sucrose at each time. Expres...

Background and Aims: Both rootstocks and mineral nutrition, particularly nitrogen (N), are known to affect many aspects of plant development including the control of scion vigour. In this study we investigated the role of the rootstock genotype in grafted grapevine responses to N supply in terms of the root and leaf ionomes, scion vigour and whole...

Root system architecture (RSA) is important for rootstock adaptation to soil resource-limited environments, but our knowledge of root traits is hampered by the lack of high-throughput root phenotyping systems for perennial fruit crops such as grapevine. Numerous approaches have been developed for non-destructive observations of RSA with the support...

Gene expression changes induced during graft union formation (the first month after grafting) in grapevine have been studied using whole genome microarrays. The genes differentially expressed between the rootstock and graft interface tissues of homo-grafts (Cabernet Sauvignon (CS) grafted onto CS) were compared at 3 and 28 days after grafting (dag)...

Although grafting is widely used in the agriculture of fruit-bearing crops, little is known about graft union formation in particular when two different species are grafted together. It is fascinating that two different plant species brought together can develop harmoniously as one organism for many decades. The objective of this study was to deter...

Grafting is widely used in the agriculture of fruit-bearing crops; rootstocks are known to confer differences in scion biomass in addition to improving other traits of agricultural interest. However, little is known about the effect of rootstocks on scion gene expression. The objective of this study was to determine whether hetero-grafting the grap...

Grafting is particularly important to the cultivation of perennial crops such as grapevine (Vitis vinifera) because rootstocks can provide resistance to soil-borne pests and diseases as well as improve tolerance to some abiotic stresses. Successful grafting is a complex biochemical and structural process beginning with the adhesion of the two graft...

Leaves of flowering plants are produced from the shoot apical meristem at regular intervals and they grow according to a developmental program that is determined by both genetic and environmental factors. Detailed frameworks for multiscale dynamic analyses of leaf growth have been developed in order to identify and interpret phenotypic differences...

Successful grafting in plants requires the development of a functional vascular system between the scion and the rootstock. Understanding the spatial organization of the graft interface is important to the evaluation of new rootstock genotypes and to the development of new grafting technologies. Until now the graft interface has only been studied u...

In grapevine (Vitis vinifera L.), rootstocks are known to alter scion development by modifying stem weight and yield. The aim of this work was to evaluate the contribution of primary growth to the rootstock effects on scion biomass. The shoot growth of Vitis vinifera cv. Cabernet Sauvignon N autografted and grafted onto Vitis riparia cv. Riparia Gl...

In much of the world’s viticulture, grapevine is cultivated grafted. The grafted plant is composed of a rootstock, responsible for nutrient and water uptake, and a scion, responsible for photosynthesis. It has long been known that rootstock genotypes affect scion vegetative growth, yield and berry quality. Despite this knowledge, the determinism of...

We have dissected the influences of apoplastic pH and cell turgor on short-term responses of leaf growth to plant water status, by using a combination of a double-barrelled pH-selective microelectrodes and a cell pressure probe. These techniques were used, together with continuous measurements of leaf elongation rate (LER), in the (hidden) elongati...

The study of leaf expansion began decades ago and has covered the comparison of a wide range of species, genotypes of a same species and environmental conditions or treatments. This has given rise to a large number of potential protocols for today's leaf development biologists. The final size of the leaf surface of a plant results from the integrat...

Background and Aims: Grafting is used in viticulture worldwide. Rootstocks are known to alter scion development or ‘confer vigour’ to varying degrees. This work examines scion/rootstock interactions in young grafted grapevines. Its aim was to determine the effects of scion and rootstock genotypes on biomass allocation within the plant. Methods and...

The study of leaf expansion began decades ago and has covered the comparison of a wide range of species, genotypes of a same species and environmental conditions or treatments. This has given rise to a large number of potential protocols for today’s leaf development biologists. The final size of the leaf surface of a plant results from the integrat...

Thaxtomin A, a phytotoxin produced by Streptomyces eubacteria, is suspected to act as a natural cellulose synthesis inhibitor. This view is confirmed by the results obtained from new chemical, molecular, and microscopic analyses of Arabidopsis thaliana seedlings treated with thaxtomin A. Cell wall analysis shows that thaxtomin A reduces crystalline...

Plant aerial development is well known to be affected by day length in terms of the timing and developmental stage of floral transition. Arabidopsis thaliana is a 'long day' plant in which the time to flower is delayed by short days and leaf number is increased. The aim of the work presented here was to determine the effects of different day length...

Genetic variability in the plasticity of leaf area expansion in response to water deficit has been reported in Arabidopsis thaliana. Here, the objective was to identify the underlying dynamic and cellular processes involved in this variability. Twenty-five accessions were subjected to identical soil water deficit treatments. In all accessions, the...

Leaf area expansion is affected by environmental conditions because of differences in cell number and/or cell size. Increases in the DNA content (ploidy) of a cell by endoreduplication are related to its size. The aim of this work was to determine how cell ploidy interacts with the regulation of cell size and with leaf area expansion. The approach...

It is well known that plant aerial development is affected by light intensity in terms of the date of flowering, the length of stems and petioles, and the final individual leaf area. The aim of the work presented here was to analyse how shade-induced changes in leaf development occur on a dynamic basis from the whole rosette level to that of the ce...

The high-throughput phenotypic analysis of Arabidopsis thaliana collections requires methodological progress and automation. Methods to impose stable and reproducible soil water deficits are presented and were used to analyse plant responses to water stress. Several potential complications and methodological difficulties were identified, including...

Leaf development is affected by both internal (genetic) and external (environmental) regulatory factors. The aim of this work was to investigate how leaf growth variables are related to one another in a range of environments. The leaf growth variables of wild-type Arabidopsis thaliana and leaf development mutants (ang4, ron2-1, elo1, elo2 and elo4)...

Several different cellular processes determine the size of the metabolically available nitrate pool in the cytoplasm. These processes include not only ion fluxes across the plasma membrane and tonoplast but also assimilation by the activity of nitrate reductase (NR). In roots, the maintenance of cytosolic nitrate activity during periods of nitrate...

p>This thesis describes an investigation of nitrate signalling in Arabidopsis thaliana leaf cells. The expression and activity of nitrate transporters and assimilatory enzymes are under complex regulation by mechanisms that are not yet fully understood. Experiments were designed to investigate the relationships between cytosolic ion activity change...

Microelectrode measurements can be used to investigate both the intracellular pools of ions and membrane transport processes of single living cells. Microelectrodes can report these processes in the surface layers of root and leaf cells of intact plants. By careful manipulation of the plant, a minimum of disruption is produced and therefore the inf...

Microelectrode measurements can be used to investigate both the intracellular pools of ions and membrane transport processes of single living cells. Microelectrodes can report these processes in the surface layers of root and leaf cells of intact plants. By careful manipulation of the plant, a minimum of disruption is produced and therefore the inf...