Members of the Arabidopsis FORKED1-LIKE gene family act to localize PIN1 in developing veins

First author: Neema Prabhakaran Mariyamma; Affiliations: University of Lethbridge (莱斯布里奇大学): Lethbridge, Canada

Corresponding author: Elizabeth A Schultz

The reticulate leaf vein (网状叶脉) pattern typical of angiosperms is proposed to have been a driving force for their evolutionary success. Vein pattern is established through auxin canalization via the auxin efflux protein PINFORMED1 (PIN1). During formation of vein loops, PIN1 cellular localization is increasingly restricted to either the basal side of cells in the lower domain or to the apical side in the upper domain. We previously identified the gene FORKED1 (FKD1) as required for PIN1 asymmetric (不对称的) localization and for the formation of closed vein loops. FKD1 encodes a plant specific protein with a Domain of Unknown Function (DUF828) and a Pleckstrin Like homology domain. The Arabidopsis genome encodes 8 similar proteins, which we term the FORKED LIKE (FL) gene family. Five FL family members localize primarily to the Trans Golgi Network (反面高尔基网) or the Golgi, and several co-localize with FKD1-GFP and RABA1c, suggesting action in the secretory pathway (分泌途径). While single FL gene family mutations do not result in vein pattern defects, triple mutants with mutations in all of FKD1, FL2 and FL3 result in a more symmetric PIN1 localization and a highly disconnected vein pattern. Our data suggest that FL genes act redundantly with FKD1 in the secretory pathway to establish appropriate PIN1 localization in provascular tissue (原维管组织).

被子植物典型的叶片网状脉被认为是其演化如此成功的一个驱动因素。通过生长素流蛋白PIN1所控制的生长素渠化是建立叶脉模式的关键。在叶脉形成过程中，PIN1蛋白的细胞定位逐渐被限制于叶片近轴和远轴区域。作者先前鉴定的FKD1基因对于PIN1蛋白的不对称分布和叶脉闭合十分重要。FKD1基因编码一个植物特异性蛋白，带有一个未知功能结构域DUF828和一个类Pleckstrin同源结构域。拟南芥基因组含有8个类似的蛋白，作者命名为FORKED LIKE即FL基因家族。其中五个FL家族成员主要定位于反面高尔基网或高尔基体中，并且一些与FKD1-GFP和RABA1c共定位，表明其可能在分泌途径发挥作用。单个的FL基因家族成员突变并未有明显的叶脉缺陷，作者构建了一个FKD1，FL2和FL3的三基因突变，结果导致了PIN1的对称分布及叶脉不能闭合。本文的研究结果显示FL基因与FKD1基因在分泌通路上存在功能冗余，一起确保了原维管组织中PIN1蛋白的正确分布。

通讯：Elizabeth A Schultz (http://directory.uleth.ca/users/schultz)

个人简介：圭尔夫大学，学士；萨斯喀彻温大学，博士。

研究方向：拟南芥叶脉模式形成，拟南芥叶形控制，生长素转运在维管组织形成中的调控作用，控制叶脉模式的基因鉴定。

doi: https://doi.org/10.1093/jxb/ery248

Journal: Journal of Experimental Botany

Published date: 03 July, 2018

（P.S. 原文下载：链接:https://pan.baidu.com/s/1qFiSsqwlF_7JjmGMbedfhQ  密码:dmu6）