缺氮胁迫下玉米组蛋白乙酰化相关酶的动态表达特征

Dynamic Expression Patterns of Corresponding Enzymes of Histone Acetylation Modification in Maize under Nitrogen Deficiency

研究缺氮对玉米自交系B73组蛋白修饰酶的影响,分析组蛋白修饰如何对玉米发育过程中土壤氮浓度的波动进行微调适应不同的氮浓度环境提供一定的理论依据。结果表明,吐丝后1~2周,缺氮雌穗的穗长和干重分别降低16.2%~19.7%和35.6%~44.4%,氮浓度在吐丝后第二周降低13.3%。利用qRT-PCR技术,对玉米苗期以及雌穗形成关键时期的组蛋白乙酰化酶(GCN5和HAT-B)和去乙酰化酶基因(HD1b,HD2,HDA101,HDA102,HDA106和HDA108)的表达进行分析,苗期缺氮8 d,除HAT-B基因外,其余7个基因的表达水平均急剧上升;缺氮36 h,HAT-B、HDA101、HD1b和HD2基因的表达量增加;缺氮处理2 d,基因HDA106和HDA108的表达水平下调。吐丝期雌穗,除HAT-B、HD1b和HD2基因外,其余5个基因都有较高的表达水平;在吐丝期前1周,缺氮导致HDA101和HDA106基因的表达水平均显著上调;基因HD1b和HD2在吐丝期后第二周表达水平则明显下调。缺氮胁迫使ZmHATs和ZmHDACs的表达可能存在协同性、功能分化性、时空摆动性以及通过不同途径调控植物对缺氮胁迫的响应等特征,说明ZmHATs和ZmHDACs在玉米缺氮胁迫适应中发挥着重要作用。

HHistone acetylation modification as key epigenetic factors in regulating the expression of genes in multiple aspects of plant growth,development,and response to stresses.The results showed that ear was 16.2%-19.7%shorter from 1 to 2 weeks after silking under N limitation compared to that with sufficient N supply.During the same time,the dry weight(DW)of the N deficient ear was 35.6%-44.4%less than that of the N sufficient ear.The N concentration abruptly dropped in the maize ear at TAS,with an approximately 13.3%decrease.qRT-PCR amplification was conducted to analyze the expression level of histone acetylases(GCN5 and HAT-B)and deacety⁃lases(HD1b,HD2,HDA101,HDA102,HDA106 and HDA108)under nitrogen deficiency.During the seedling stage,all HTAs and HDACs were up-regulated at 8 days,except HAT-B.The expression of HAT-B,HDA101,HD1b and HD2 also increased at 36 h under nitrogen limitation.After low nitrogen treatment for 2 days,the expression of HDA106 and HDA108 were down-regulated.At silking stage,except HAT-B,HD1b and HD2 genes,all genes had a higher expression levels under nitrogen deficiency.At one week before silking,the expression of HDA101 and HDA106 were significantly up-regulated due to nitrogen deficiency.However,the expression of HD1b and HD2 were significantly down-regulated at two weeks after silking.The regular expression of histone acetylases and deacetylases under nitrogen deficiency indicated that an important role of histone acetylation modification in maize’s adaptation to nitrogen deficiency stress during growth and development.