AtBET5 is essential for exine pattern formation and apical meristem organization in Arabidopsis

作   者：张进，陈军，王丽娟，赵树堂，李建波，刘伯斌，李红英，齐星云，郑焕泉，卢孟柱
期刊名称：Plant Science
影响因子：3.712
卷 期 号：274
页     码：231-241
关键词：Arabidopsis thaliana; BET5; TRAPP; Apical Meristem; Auxin; PIN1/2
论文摘要：
BET5 is a component of trafficking protein particle (TRAPP) which has been studied
extensively in non-plant organisms where they are involved in membrane traffickingwithin Golgi and between Golgi and early endosomes. Recent analysis of TRAPP in
different classes of organisms indicates that TRAPP function might exhibit differences
among organisms. A single copy of the BET5 gene named AtBET5 was found in the
Arabidopsis genome based on sequence similarity. Developmental phenotype and the
underlying mechanisms have been characterized upon transcriptional knock-down lines
generated by both T-DNA insertion and RNAi. Pollen grains of the T-DNA insertional line
present reduced fertility and pilate exine instead of tectate exine. Perturbation of the
AtBET5 expression by RNAi leads to apical meristematic organization defects and reduced
fertility as well. The reduced fertility was due to the pollination barrier caused by an altered
composition and structure of pollen walls. Auxin response in root tip cells is altered and
there is a severe disruption in polar localization of PIN1-GFP, but to a less extent of PIN2-
GFP in the root tips, which causes the apical meristematic organization defects and might
also be responsible for the secretion of sporopollenin precursor or polar targeting of
sporopollenin precursor transporters.