StH2A-1正向调控本氏烟顶端优势和正常开花  

StH2A-1 Positively Regulates the Apical Dominance and Floral on Time in Nicotiana benthamiana

作　　者：乔丽媛[1] 拓宁 伍涵宇 殷倩 张晓萍[1] 姚新灵[1] 

机构地区：[1]宁夏大学生命科学院/西部特色生物资源保护及利用教育部重点实验室,银川750021

出　　处：《农业生物技术学报》2017年第12期1940-1949,共10页Journal of Agricultural Biotechnology

基　　金：国家自然科学基金项目(No.31160236和No.31360275);宁夏回族自治区农业育种专项(No.2014NYYZ02)

摘　　要：核小体中组蛋白(histone,H2A)与其变异体替换调控基因表达,尽管研究已揭示了拟南芥(Arabidopsis thaliana)H2A参与生长发育调控,但植物H2A家族不同成员功能的研究极为有限;本研究克隆了马铃薯(Solanum tuberosum)St H2A-1基因c DNA,转化反义St H2A-1 c DNA于本氏烟(Nicotiana benthamiana)体内表达,H2A减少表达株系h2a-1叶片Nb H2A蛋白质含量低于对照31%,表现顶端优势缺失和开花推迟的表型;St H2A-1预测氨基酸序列检索本氏烟基因组数据库,识别了5个与St H2A-1相似性高于97%的本氏烟Nb H2A,其N端均独具不同长度多聚丙氨酸基序;不同Nb H2A反转录聚合酶链式反应(reverse transcription plymerase chain reaction,RT-PCR)结果显示,h2a-1株系叶片多聚丙氨酸Nb H2A编码基因m RNA积累明显低于野生型(wild type,WT),但其他Nb H2A m RNA在h2a-1中积累显著增加,表明不同Nb H2A彼此可能功能互补;成花基因特异引物RT-PCR结果显示,h2a-1株系中ELF4(EARLY FLOWERING 4)、CO(CONSTANS)和FT(FLOWERING LOCUS T)基因m RNA积累下调,意味着Nb H2A-1参与了成花基因的转录关联。研究结果表明,St H2A-1基因与顶端优势形成和正常开花关联,且正向调控植物生长发育。该研究结果有助于进一步理解H2A的生长发育调控功能。The replacement of histone（H2A） with its variants in nucleosome regulates gene expression in plant. Although it is revealed that At H2A involves in regulation of growth and development in Arabidopsis thaliana, study on function of H2A family members in plant is rare. In this study, A StH2A-1 cDNA was isolated from potato（Solanum tuberosum）. A Nicotiana benthamiana transgenic line h2 a-1, expressing antisense StH2A-1 cDNA displayed 31% lower leaf H2A contents than wild type（WT）, leading to an apical dominancedeficient and late-flowering phenotype. BLAST outcome in Nicotiana benthamiana genome database showed that 4 NbH2As, sharing higher than 97% similarity with StH2A-1 uniquely contain a poly（Aln） motif with various length in the N-terminal of the amino acid sequences. Outcome of the reverse transcription polymerase chain reaction（RT-PCR） showed that accumulation of NbH2A mRNA, encoding NbH2A with N-terminal poly（Aln） was lower in the h2 a-1 line than it in WT. The other NbH2As displayed a clearly higher mRNA accumulation in the h2 a-1 line than it in WT. This suggested that NbH2As with and without N-terminal poly（Aln） may be complemented one another to function in gene expression regulation. RT-PCR also exhibited that mRNA accumulations of floral genes, including ELF4（EARLY FLOWERING 4）, CO（CONSTANS） and FT（FLOWERING LOCUS T） in the h2 a-1 line were down-regulated, suggesting that NbH2As with N-terminal poly（Aln） may involve in transcription of those genes. As a conclusion, StH2A-1 is associated with formation of apical dominance and regular flowering and positively regulates plant growth and development. The result may contribute to further understanding on function of H2A in plant growth and development.

关 键 词：组蛋白(H2A) 抑制 成花 本氏烟 

分 类 号：S18[农业科学—农业基础科学] Q75[生物学—分子生物学]