Pepper Rootstock and Scion Physiological Responses Under Drought Stress

作者：Lidia López‐Serrano, Guillermo Canet-Sanchis, Gabriela Vuletin Selak, Consuelo Penella, A. San Bautista, S. López-Galarza, Ángeles Calatayud · 发表于：Frontiers in Plant Science · 年份：2019 · DOI：10.3389/fpls.2019.00038 · 被引用次数：378 · 研究领域：Plant Disease Management Techniques、Nematode management and characterization studies、Plant Virus Research Studies

In vegetables, tolerance to drought can be improved by grafting commercial varieties onto drought tolerant rootstocks. Grafting has emerged as a tool that copes with drought stress. In previous results, the A25 pepper rootstock accession showed good tolerance to drought in fruit production terms compared with non grafted plants and other rootstocks. The aim of this work was to study if short-term exposure to drought grafted plants using A25 as a rootstock would show tolerance to drought now. To fulfill this objective, some physiological processes involved in roots (rootstock) and leaves (scion) of grafted pepper plants were analyzed. Pepper plants not grafted (A), self-grafted (A/A) and grafted onto a tolerant pepper rootstock A25 (A/A25) were grown under severe water stress induced by PEG addition (-0.55 MPa) or under control conditions for 7 days in hydroponic pure solution. According to our results, water stress severity was alleviated by using the A25 rootstock in grafted plants (A/A25), which indicated that mechanisms stimulated by roots are essential to withstand stress. A/A25 had a bigger root biomass compared with plants A and A/A that resulted in better water absorption, water retention capacity and a sustained CO2 assimilation rate. Consequently, plants A/A25 had a better carbon balance, supported by greater nitrate reductase activity located mainly in leaves. In the non grafted and self-grafted plants, the photosynthesis rate lowered due to stomatal closure, which ...