拟南芥RALF多肽家族的功能多样性初步分析

doi:10.13560/j.cnki.biotech.bull.1985.2018-0921

摘要/Abstract

摘要： 绿色植物中的快速碱化因子（Rapid alkalinization factor,RALF）为一类进化保守的多肽信号分子,以基因家族形式存在。模式植物拟南芥中至少存在35个RALF基因成员,前期研究显示拟南芥RALF家族的部分成员,比如RALF1/23,RALF4/19 可分别作为CrRLK1L类蛋白受体激酶家族成员FERONIA及BUPS1/2的配体,调控细胞伸长、植物免疫应答及双受精等过程,但是RALF家族其他成员是否具有生物学活性,以及不同成员之间是否具有功能性差异均尚不清楚。因此,本研究异源表达了19个代表性的RALF,并对其生物学活性和功能性差异进行了分析。实验结果表明,19个RALF均对根的生长起到不同程度的抑制作用,进一步挑选了部分代表性RALF成员进行了活性氧（ Reactive oxygen species,ROS）迸发及丝裂原活化蛋白激酶（Mitogen-activated protein kinase,MAPK）磷酸化实验分析,实验结果表明,我们确证了11个RALF蛋白参与了MAPK信号的响应,同时,证实16个RALF蛋白抑制了由flg22引起的ROS的释放。此外,不同RALF成员在下胚轴细胞伸长上的作用也存在明显差异,比如RALF10促进下胚轴的伸长。以上研究结果表明不同RALF之间既存在功能冗余性,又存在功能性差异。本研究丰富了对RALF功能复杂性和多样性的认识。

关键词: 拟南芥, 根长, 下胚轴, 植物细胞免疫, RALF10

Abstract: The Rapid Alkalinization Factor（RALF）,which exists as a gene family,is a kind of conservative peptide molecule in green plant. There are at least 35 RALF genes in model plant Arabidopsis thaliana. Previous studies show that certain members of RALF family,such as RALF1/23 and RALF4/19 function as the ligand of CrRLK1L members FERONIA and BUPS1/2 respectively,thus regulate cell elongation,plant immune response and double fertilization. However,whether other RALF members have biological activity and whether distinct RALF have varied functions are still unclear. Here,we have expressed 19 heterogeneous representative RALFs and analyzed their biological activities and functional diversity. The experimental results showed that all 19 RALF proteins inhibited root growth at various extents. Some representative RALF members were further selected for flg22-induced ROS release and MAPK phosphorylation level assays. From the results,we confirmed that 11 RALF proteins participated in the response of MAPK signal,and also confirmed that 16 RALF proteins inhibited the ROS release caused by flg22. In addition,there were significant differences in the regulation of hypocotyl elongation,for instance,RALF10 promoted hypocotyl elongation. The above results suggest that different RALF have both functional redundancy and differences. This study complements and improves the understanding of the complexity and diversity of RALF functions.

Key words: Arabidopsis thaliana, root length, hypocotyl, plant immunity, RALF10

强晓楠, 李鑫, 陈佳, 廖红东, 于峰. 拟南芥RALF多肽家族的功能多样性初步分析[J]. 生物技术通报, 2019, 35(1): 2-10.

QIANG Xiao-nan, LI Xin, CHEN Jia, LIAO Hong-dong, YU Feng. Preliminary Analysis of Functional Diversity of RALF Peptide Family in Arabidopsis thaliana[J]. Biotechnology Bulletin, 2019, 35(1): 2-10.

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