外源IAA对马尾松幼苗茎干次生生长的影响  

Effects of Exogenous IAA on Stem Secondary Growth of Pinus massoniana Seedlings

作　　者：周紫晶 范付华 尚先文 覃慧娟 王聪慧 丁贵杰 谭健晖[2] Zhou Zijing;Fan Fuhua;Shang Xianwen;Qin Huijuan;Wang Conghui;Ding Guijie;Tan Jianhui(Institute for Forest Resources and Environment of Guizhou Province,Key Laboratory of Forest Cultivation in Plateau Mountain of Guizhou Province,College of Forestry,Guizhou University,Guiyang 550025;Guangxi Zhuang Autonomous Region Forestry Research Institute,Nanning 530002)

机构地区：[1]贵州大学贵州省森林资源与环境研究中心,贵州省高原山地林木培育重点实验室,贵州大学林学院,贵阳550025 [2]广西壮族自治区林业科学研究院,南宁530002

出　　处：《林业科学》2021年第9期42-51,共10页Scientia Silvae Sinicae

基　　金：国家重点研发计划后补助(黔科合平台人才[2018]5261号);广西创新驱动发展专项(桂科AA17204087-4);国家重点研发计划(2017YFD0600302);贵州省一流学科建设项目(GNYL[2017]007)。

摘　　要：【目的】对2年生马尾松幼苗进行不同浓度IAA喷施处理,结合生理生化、形态解剖结构及转录组水平变化等综合分析,揭示外源IAA对马尾松苗期茎干次生生长的影响机制,为阐明马尾松苗期茎干次生生长的分子调控机制奠定基础,可以为培育速生高产的马尾松新品系提供一定的理论参考。【方法】对2年生马尾松幼苗进行不同浓度IAA(0、1、50、100 mg·L^(-1))喷施处理,处理160天后进行生长指标、解剖结构、生理生化指标的测定;通过高通量转录组测序鉴定差异表达基因,对差异表达基因进行GO和KEGG功能分析。【结果】IAA处理对2年生马尾松的地径、细胞生长(木质部、韧皮部厚度以及木质部细胞层数)、木材主要成分(木质素、纤维素及半纤维素含量)及内源激素含量(生长素、赤霉素及油菜素内酯)具有显著的促进作用(P<0.05);通过Illumina测序技术对对照组和IAA处理的6个cDNA文库进行测序,最终得到IAA处理后差异表达基因778个(包括482个上调表达基因和296个下调表达基因),GO分析表明这些差异基因主要富集于细胞成分、分子功能和生物过程中共计22个类别,KEGG分析表明它们参与了64种不同的途径,并筛选出与马尾松次生生长相关的差异表达基因(BRL1、GASA6、CAD和CESA2等)。【结论】IAA处理能够改变内源激素含量,促进细胞分裂,增加木质素、纤维素和半纤维素积累,从而促进马尾松茎干的次生生长。【Objective】Pinus massoniana is a unique fast-growing tree species in China and is one of the main afforestation tree species in southern China,which has high economic and ecological value.Auxin has a significant effect on the secondary growth of plants.An in-depth study on the secondary growth of the stem of P.massoniana can provide theoretical basis for breeding new varieties of P.massoniana with fast growth and high yield.In this study,two-year-old P.massoniana seedlings were sprayed with different concentrations of IAA.The effects of exogenous IAA on the secondary growth of P.massoniana seedlings were analyzed in combination with physiological,biochemical,morphological traits and anatomical structures and transcriptome changes.This study could lay a foundation for elucidating molecular regulation mechanism of stem secondary growth of P.massoniana seedlings.【Method】Two-year-old P.massoniana seedlings were sprayed with different concentrations of IAA(0,1,50,100 mg·L^(-1)).After 160 days of treatment,growth traits,anatomic structure,physiological and biochemical properties were measured.The differentially expressed genes were identified by high-throughput transcriptome sequencing,and analyzed by GO and KEGG.【Result】IAA treatment significantly promoted the ground diameter,cell growth(xylem and phloem thickness and xylem cell layers),physiological components of wood(lignin,cellulose and hemicellulose),endogenous hormone contents(auxin,gibberellin and brassinolide)of two-year-old P.massoniana(P<0.05).Six cDNA libraries of CK and IAA were sequenced by Illumina sequencing,778 differentially expressed genes(including 482 up-regulated genes and 296 down-regulated genes)were obtained.GO analysis showed that these differential genes were mainly involved in 22 categories of cell components,molecular functions and biological processes,and KEGG analysis showed that they were involved in 64 different pathways.Differentially expressed genes related to secondary growth of P.massoniana were screened,such as BRL1,GAS

关 键 词：马尾松 IAA 次生生长 转录组 

分 类 号：S718.43[农业科学—林学] S718.46