Grünhofer Paul, Heimerich Ines, Herzig Lena, Pohl Svenja, Schreiber Lukas
Department of Ecophysiology, Institute of Cellular and Molecular Botany, University of Bonn, Kirschallee 1, 53115, Bonn, Germany.
Stress Biol. 2023 Jul 21;3(1):24. doi: 10.1007/s44154-023-00103-3.
Populus is an important tree genus frequently cultivated for economical purposes. However, the high sensitivity of poplars towards water deficit, drought, and salt accumulation significantly affects plant productivity and limits biomass yield. Various cultivation and abiotic stress conditions have been described to significantly induce the formation of apoplastic barriers (Casparian bands and suberin lamellae) in roots of different monocotyledonous crop species. Thus, this study aimed to investigate to which degree the roots of the dicotyledonous gray poplar (Populus × canescens) react to a set of selected cultivation conditions (hydroponics, aeroponics, or soil) and abiotic stress treatments (abscisic acid, oxygen deficiency) because a differing stress response could potentially help in explaining the observed higher stress susceptibility. The apoplastic barriers of poplar roots cultivated in different environments were analyzed by means of histochemistry and gas chromatography and compared to the available literature on monocotyledonous crop species. Overall, dicotyledonous poplar roots showed only a remarkably low induction or enhancement of apoplastic barriers in response to the different cultivation conditions and abiotic stress treatments. The genetic optimization (e.g., overexpression of biosynthesis key genes) of the apoplastic barrier development in poplar roots might result in more stress-tolerant cultivars in the future.
杨树是一种重要的树木属，常出于经济目的而种植。然而，杨树对水分亏缺、干旱和盐分积累的高度敏感性显著影响植物生产力并限制生物量产量。已描述了各种栽培和非生物胁迫条件可显著诱导不同单子叶作物物种根系中质外体屏障（凯氏带和木栓质层）的形成。因此，本研究旨在调查双子叶银白杨（Populus × canescens）的根系对一组选定的栽培条件（水培、气培或土壤）和非生物胁迫处理（脱落酸、缺氧）的反应程度，因为不同的胁迫反应可能有助于解释观察到的更高胁迫敏感性。通过组织化学和气相色谱法分析了在不同环境中培养的杨树根系的质外体屏障，并与有关单子叶作物物种的现有文献进行了比较。总体而言，双子叶杨树根系对不同的栽培条件和非生物胁迫处理仅表现出非常低的质外体屏障诱导或增强。杨树根系质外体屏障发育的基因优化（例如，生物合成关键基因的过表达）未来可能会产生更耐胁迫的品种。
