Reciprocal Grafting Reveals Differential Metabolic Responses Between Robusta Clones with Contrasting Tolerances to Drought

Abstract

Faced with global warming, the surface area of coffee cultivation regions is expected to diminish significantly in the near future. As a result, new varieties or agronomical practices improving drought tolerance need to be found. The aim of this work is to characterize drought tolerance of Coffea canephora genotypes and their reciprocal grafted plants with physiological tools and biochemical analyses. Under greenhouse conditions, control plants (sensitive or tolerant) and reciprocal grafted plants submitted to 14 days of water deprivation show variations of the monitored parameters, such as soil and leaf water potential, stomatal conductance, and osmoprotectant compounds (sugars, polyols, amino acids). The variations observed confirm the differences between the phenotypes defined as drought-tolerant and drought-sensitive. Reciprocal grafting shows enhanced and contrasting situations. A sensitive clone grafted onto tolerant rootstock presents higher tolerance to drought and physiological or biochemical parameters similar to a drought-tolerant clone. The opposite is observed for tolerant clones grafted onto a sensitive one. More contrasted results are obtained with glucose, fructose, proline, and mannitol content which could be used as indicators for drought tolerance. Our finding shows strong variability for drought tolerance in our Robusta clones and demonstrates the impact of grafting on physiological and biochemical parameters linked to drought tolerance. The use of drought-tolerant rootstock leads to better regulation of water management and biochemical composition of the scion in drought-sensitive clones. This could be an approach to improving drought tolerance of Coffea canephora genotypes and to limiting the impact of global warming on coffee farming.

Effect of Low-Temperature Tolerant Rootstocks on the Growth and Fruit Quality of Watermelon in Semi-Forcing and Retarding Culture

“…The main vine of non-grafted watermelons in the early growth stage when plants were exposed to high temperature was the longest. The reciprocal grafting of a stress-tolerant scion onto a stress-sensitive rootstock has been reported to reveal that the stress-sensitive rootstock weakened the stress tolerance of scions [50][51][52].…”

Grafting enhances plants drought resistance: Current understanding, mechanisms, and future perspectives

“…For example, in some grafted combinations, when drought-resistant plants and drought-sensitive plants were used as rootstocks and scions, respectively, the grafted plants had better drought resistance than the contrary combinations where drought-resistant plants and drought-sensitive plants were respectively used as scions and rootstocks. However, sometimes despite the drought-resistant soybean being used as the scion or the rootstock, the grafted plants could maintain photosynthesis ( Li et al., 2019 ; Spiral et al., 2022 ). This genetic limitation is more obvious when we consider fruit quality.…”

Physiological quality of seeds of Coffea canephora from early and late clones during maturation

“…Propagation of C. canephora is traditionally done by cuttings, with less emphasis on seeds. However, seed propagation has increased due to the demand for rootstocks resistant to nematodes and drought conditions, and their compatibility with https://doi.org/10.1590/1678-4499.20230200 C. arabica for the cultivation of more resistant seedlings (Gonçalves et al 2021, López-García and Cruz-Castillo 2019, Spiral et al 2023. In this context, a seminal cultivar 'Conquista ES8152' was launched, offering genotypes with desirable attributes, such as intermediate to late maturity, vigor, drought tolerance, rust resistance, and high drinking quality (Ferrão et al 2019).…”