Wu Jiandong, Chen Long, Chen Mingchao, Zhou Wei, Dong Qing, Jiang Haiyang, Cheng Beijiu
National Engineering Laboratory of Crop Stress Resistance, College of Life Science, Anhui Agricultural University, Hefei, China.
Front Plant Sci. 2019 Apr 12;10:465. doi: 10.3389/fpls.2019.00465. eCollection 2019.
Starch synthesis is a complex process that influences crop yield and grain quality in maize. Many key enzymes have been identified in starch biosynthesis; however, the regulatory mechanisms have not been fully elucidated. In this study, we identified a DOF family gene, , through transcriptome sequencing analysis. Real-time PCR indicated that was highly expressed in maize endosperm, with lower expression in leaves and tassels. is a typical DOF transcription factor (TF) that is localized to the nucleus and possesses transcriptional activation activity, and its transactivation domain is located in the C-terminus (amino acids 227-351). Overexpression of can increase starch content and decrease the contents of soluble sugars and reducing sugars. In addition, abnormal starch structure in transgenic maize was also observed by scanning electron microscopy (SEM). Furthermore, the expression levels of starch synthesis-related genes were up-regulated in -expressing transgenic maize. ZmDOF36 was also shown to bind directly to the promoters of six starch biosynthesis genes, , , , , , and in yeast one-hybrid assays. Transient expression assays showed that ZmDOF36 can activate the expression of and in tobacco leaves. Collectively, the results presented here suggest that ZmDOF36 acts as an important regulatory factor in starch synthesis, and could be helpful in devising strategies for modulating starch production in maize endosperm.
淀粉合成是一个影响玉米作物产量和籽粒品质的复杂过程。在淀粉生物合成过程中已鉴定出许多关键酶；然而，其调控机制尚未完全阐明。在本研究中，我们通过转录组测序分析鉴定出一个DOF家族基因， 。实时定量PCR表明， 在玉米胚乳中高表达，在叶片和雄穗中表达较低。 是一个典型的DOF转录因子（TF），定位于细胞核并具有转录激活活性，其反式激活结构域位于C端（氨基酸227 - 351）。过表达 可增加淀粉含量，降低可溶性糖和还原糖的含量。此外，通过扫描电子显微镜（SEM）还观察到转基因玉米中淀粉结构异常。此外，在过表达 的转基因玉米中，淀粉合成相关基因的表达水平上调。酵母单杂交试验表明，ZmDOF36还可直接与6个淀粉生物合成基因 、 、 、 、 和 的启动子结合。瞬时表达试验表明，ZmDOF36可激活烟草叶片中 和 的表达。总体而言，本文结果表明ZmDOF36在淀粉合成中起重要调控因子的作用，有助于制定调控玉米胚乳淀粉产量的策略。
