Liu Hanmei, Wang Yongbin, Liu Lijun, Wei Bin, Wang Xieqin, Xiao Qianlin, Li Yangping, Ajayo Babatope Samuel, Huang Yubi
College of Life Science, Sichuan Agricultural University, Ya'an, China.
College of Agronomy, Sichuan Agricultural University, Chengdu, China.
Front Plant Sci. 2022 Jul 22;13:895763. doi: 10.3389/fpls.2022.895763. eCollection 2022.
Starch, the major component of cereal grains, affects crop yield and quality and is widely used in food and industrial applications. The biosynthesis of maize starch is a complex process involving a series of functional enzymes. However, the sophisticated regulatory mechanisms of starch biosynthetic genes have not been fully elaborated. The basic/helix-loop-helix (bHLH) transcription factors are widely distributed in eukaryotes and participate in many physiological processes. In this study, 202 bHLH encoding genes were identified in the maize genome by Blast method. gene, which belongs to the ICE subfamily of the bHLH family, was obtained and expressed mainly in maize filling endosperm and co-expressed with 14 starch biosynthesis genes. Based on the comparative analyses across different plant species, we revealed that the gene structures and protein domains of the ICE subfamily were conserved between monocots and dicots, suggesting their functional conservation feature. Yeast activation and subcellular localization assays suggested that ZmICE1 had transcriptional activation activity and localized in the nucleus. Yeast one-hybrid assays confirmed that ZmICE1 could directly bind to the promoters of and . Transient gene expression analysis in maize endosperm revealed that ZmICE1 positively regulated the expression of , but inhibited the expression of . Our results indicated that ZmICE1 could function as a regulator of maize starch biosynthesis.
淀粉是谷物的主要成分，影响作物产量和品质，并且在食品和工业应用中广泛使用。玉米淀粉的生物合成是一个涉及一系列功能酶的复杂过程。然而，淀粉生物合成基因复杂的调控机制尚未完全阐明。碱性/螺旋-环-螺旋（bHLH）转录因子广泛分布于真核生物中，并参与许多生理过程。在本研究中，通过Blast方法在玉米基因组中鉴定出202个编码bHLH的基因。获得了属于bHLH家族ICE亚家族的基因，其主要在玉米灌浆胚乳中表达，并与14个淀粉生物合成基因共表达。基于对不同植物物种的比较分析，我们发现ICE亚家族的基因结构和蛋白质结构域在单子叶植物和双子叶植物之间是保守的，表明它们具有功能保守特性。酵母激活和亚细胞定位分析表明ZmICE1具有转录激活活性且定位于细胞核。酵母单杂交分析证实ZmICE1可以直接结合和的启动子。玉米胚乳中的瞬时基因表达分析表明ZmICE1正向调控的表达，但抑制的表达。我们的结果表明ZmICE1可以作为玉米淀粉生物合成的调节因子发挥作用。
