《植物生理学报》 2015, 51(12): 2133-2142

棉花LIM蛋白基因家族的进化及表达特征分析

杨洋, 李波, 胡文冉, 张经博, 范玲^*

新疆农业科学院核技术生物技术研究所, 乌鲁木齐830091

通信作者：范；E-mail: fanling@xaas.ac.cn；Tel: 0991-4527003

摘　要：

植物LIM蛋白参与细胞骨架的调节及调控次生细胞壁的发育。本研究在雷蒙德氏棉(D5)、亚洲棉(A2)基因组和陆地棉的A、D亚基因组中分别鉴定出14个LIM基因。陆地棉GhLIM基因在2个亚组间的染色体上的分布及基因的复制模式是一致的。推测其复制发生在其祖先同可可(6个LIM)分开之后, A2、D5基因组分化之前; 陆地棉LIM除多倍体化使其数目加倍外, 没有基因复制与丢失事件发生。蛋白系统进化分析表明, 所有被子植物LIM蛋白可以划分为4个亚组(部分具有小亚组): αLIM1 (FLIM1、WLIM1、PLIM1)、βLIM1、γLIM2 (WLIM2)、δLIM2 (PLIM2-I、PLIM2-II)。陆地棉GhLIM的同源复制基因分别在WLIM2和PLIM2-I、PLIM2-II中聚为独立的分支。通过分析深度测序表达谱, 发现陆地棉GhLIM有3种表达类型: 组成型表达的GhLIM1、2 (FLIM), GhLIM3 (WLIM1), GhLIM13 (βLIM1)和GhLIM4、8、14 (WLIM2); 雄蕊中优势表达的GhLIM7、9 (PLIM2-I), GhLIM5、6、10、11 (PLIM2-II); 在雄蕊和纤维中优势表达的GhLIM12 (PLIM2-I)。实时荧光定量PCR分析表明, GhLIM基因各成员在不同的纤维发育阶段具有不同的表达特征, GhLIM1、13、14在纤维的快速伸长期(5~15 DPA)上调表达, 在15 DPA表达量最高; GhLIM2则在纤维次生壁发育期(18~28 DPA)显著上调表达, 在28 DPA表达量最高。而GhLIM12在10~23 DPA持续高表达, 在28 DPA则没有表达。上述结果说明GhLIM家族基因在纤维发育的不同阶段发挥着不同的功能。

关键词：棉花; LIM; 纤维发育; 基因复制; 基因表达模式

收稿：2015-09-18   修定：2015-11-17

资助：新疆维吾尔自治区高技术项目(201111116)、国家高技术研究发展计划项目(“863”项目) (2012AA101108-05-04)和新疆维吾尔自治区自然科学基金(2015211B013)。

Evolution and Expression Analysis of the LIM Protein Gene Family in Cotton

YANG Yang, LI Bo, HU Wen-Ran, ZHANG Jing-Bo, FAN Ling^*

Institute of Nulclear and Biological Technologies, Xinjiang Academy of Agricultural Sciences, Urumuqi 830091, China

Corresponding author: FAN Ling; E-mail: fanling@xaas.ac.cn; Tel: 0991-4527003

Abstract:

Plant LIM acts as an actin bundler to facilitate elongation of cells and also functions as a transcription factor involved in secondary cell wall development. In this study, 14 putative LIM genes were identified from the whole genomes of Gossypium raimondii (D5), G. arboreum (A2), and 2 subgenomes (A, D) of G. hirsutum, respectively. In G. hirsutum, the distribution and the duplication patterns of LIM family members on each couple homology chromosomes were consistent, suggesting that the LIM gene may had duplicated since the ancestors of cacao and diploid cottons had diverged, and before the divergence of the D5 and A2 diploid cottons, and GhLIMs may not experienced a single duplicate or gene loss in G. hirsutum, except the chromosome redoubling. The phylogenetic analysis suggested that the angiosperm LIM proteins could clustered into four groups (subgroups are gathered within groups): αLIM1 (FLIM1, WLIM1, PLIM1), βLIM1, γLIM2 (WLIM2), δLIM2 (PLIM2-I, PLIM2-II); the duplicated homologs of GhLIM were clusted in WLIM2, PLIM2-I, PLIM2-II subgroups respectively. The GhLIM genes expressing profiling analysis showed that, there were 3 types of expressing patterns: GhLIM1/2 (FLIM), GhLIM3 (WLIM1), GhLIM13 (βLIM1) and GhLIM4/8/14 (WLIM2) were widely expressed in different tissues; GhLIM7/9 (PLIM2-I) and Gh-LIM5/6/10/11 (PLIM2-II) were preferentially expressed in the stamen; LIM12 (PLIM2-I) were strongly expressed in stamen and fiber. Quantitative PCR results of GhLIM exhibited different expression patterns during the process of fiber development, the expressing of GhLIM1 was up-regulated in elongation stage, and peaked in 15 DPA; GhLIM2 was redominant up-regulated at stage of secondary wall biosynthesis, and peaked in 28 DPA; and the expression level of GhLIM12 was constantly high during 10–23 DPA, and disappeared in 28 DPA, these result indicating different subfunctionalisations of GhLIM genes in different fiber development phases.

Key words: cotton; LIM; fiber development; gene duplication; gene expression profiling