Identification of phloem-associated translatome alterations during leaf development in Prunus domestica L.

First author: Tamara D. Collum; Affiliations: Institute for Bioscience and Biotechnology Research (美国马里兰大学生命科学与生物技术研究所): College Park, USA

Corresponding author: James N. Culver

Phloem plays a fundamental role in plants by transporting hormones, nutrients, proteins, RNAs, and carbohydrates essential for plant growth and development. However, the identity of the underlying phloem genes and pathways remain enigmatic especially in agriculturally important perennial crops, in part, due to the technical difficulty of phloem sampling. Here, we used two phloem-specific promoters and a translating ribosome affinity purification (TRAP) strategy to characterize the phloem translatome during leaf development at 2, 4, and 6 weeks post vernalization in plum (Prunus domestica L.). Results provide insight into the changing phloem processes that occur during leaf development. These processes included the early activation of DNA replication genes that are likely involved in phloem cell division during leaf expansion, as well as the upregulation of phloem genes associated with sink to source conversion, induction of defense processes, and signaling for reproduction. Combined these results reveal the dynamics of phloem gene expression during leaf development and establish the TRAP system as a powerful tool for studying phloem-specific functions and responses in trees.

植物韧皮部的作用主要是运输植物激素、营养物质、蛋白、RNA以及碳水化合物，这些物质都是植物的生长和发育所必需的。然而，有关韧皮部中起作用的基因和通路还不清楚，尤其是农艺上比较重要的多年生作物，其中一个可能的原因就是韧皮部的样本比较难取。本文中，作者利用两个韧皮部特异性表达启动子以及一个叫做翻译核糖体亲和纯化（TRAP）的方法来研究欧洲李在春化2、4、6周后叶子发育时韧皮部组织翻译的蛋白情况。研究结果揭示了韧皮部组织中的生物进程在叶子发育时期的动态变化。这些进程包括DNA复制相关基因的早期激活，可能在叶片扩展时参与韧皮部细胞的分裂。同时，韧皮部由“库”到“源”转变相关的基因上调表达，防御相关的进程受到诱导，以及与生殖相关的信号通路被激活。综上，这些研究结果揭示了韧皮部组织在叶片发育时期的动态基因表达，并且说明了TRAP系统是一个研究林木韧皮部功能和响应的非常有用的工具。

通讯：James N. Culver（https://bioe.umd.edu/clark/faculty/105/James-Culver）

个人简介：1991年，加利福尼亚大学河滨分校，博士。

研究方向：毒理生物学。

doi: https://doi.org/10.1038/s41438-018-0092-4

Journal: Horticulture Research

Published date: February 01, 2019