Zhang Li, Merlin Isabelle, Pascal Stéphanie, Bert Pierre-François, Domergue Frédéric, Gambetta Gregory A
EGFV Bordeaux-Sciences Agro INRA Univ. Bordeaux ISVV Villenave d'Ornon France.
Laboratoire de Biogenèse Membranaire CNRS - Univ. Bordeaux - UMR 5200 Bâtiment A3 - INRA Bordeaux Aquitaine Villenave d'Ornon France.
Plant Direct. 2020 Nov 22;4(11):e00278. doi: 10.1002/pld3.278. eCollection 2020 Nov.
The permeability of roots to water and nutrients is controlled through a variety of mechanisms and one of the most conspicuous is the presence of the Casparian strips and suberin lamellae. Roots actively regulate the creation of these structures developmentally, along the length of the root, and in response to the environment, including drought. In the current study, we characterized the suberin composition along the length of grapevine fine roots during development and in response to water deficit, and in the same root systems we quantified changes in expression of suberin biosynthesis- and deposition-related gene families (via RNAseq) allowing the identification of drought-responsive suberin-related genes. Grapevine suberin composition did not differ between primary and lateral roots, and was similar to that of other species. Under water deficit there was a global upregulation of suberin biosynthesis which resulted in an increase of suberin specific monomers, but without changes in their relative abundances, and this upregulation took place across all the developmental stages of fine roots. These changes corresponded to the upregulation of numerous suberin biosynthesis- and export-related genes which included orthologs of the previously characterized AtMYB41 transcriptional factor. Functional validation of two grapevine MYB41 orthologs, VriMYB41 and VriMYB41-like, confirmed their ability to globally upregulate suberin biosynthesis, export, and deposition. This study provides a detailed characterization of the developmental and water deficit induced suberization of grapevine fine roots and identifies important orthologs responsible for suberin biosynthesis, export, and its regulation in grape.
根系对水分和养分的渗透性是通过多种机制来控制的,其中最显著的机制之一是凯氏带和栓质层的存在。根系会沿着根的长度,在发育过程中以及响应包括干旱在内的环境时,积极调控这些结构的形成。在本研究中,我们对葡萄细根在发育过程中以及响应水分亏缺时沿根长的栓质组成进行了表征,并且在同一根系中,我们通过RNA测序对栓质生物合成和沉积相关基因家族的表达变化进行了定量分析,从而确定了干旱响应性栓质相关基因。葡萄的栓质组成在初生根和侧根之间没有差异,并且与其他物种相似。在水分亏缺条件下,栓质生物合成出现整体上调,导致栓质特异性单体增加,但它们的相对丰度没有变化,并且这种上调在细根的所有发育阶段均会发生。这些变化与众多栓质生物合成和输出相关基因的上调相对应,其中包括先前已鉴定的AtMYB41转录因子的直系同源基因。对两个葡萄MYB41直系同源基因VriMYB41和VriMYB41-like的功能验证,证实了它们能够整体上调栓质生物合成、输出和沉积。本研究详细表征了葡萄细根发育和水分亏缺诱导的栓质化过程,并鉴定了负责葡萄栓质生物合成、输出及其调控的重要直系同源基因。