Plant Cell and Environ:浙大殷学仁教授揭示枇杷果实冷害木质化转录
2016年3月23日，国际杂志《Plant Cell and Environment》在线发表浙江大学农业科学与生物技术学院殷学仁教授领衔的果实品质生物学研究团队的最新研究发现，研究揭示了热激响应因子(HSF)参与枇杷冷害的新机制，研究题为“Regulation of loquat fruit low temperature response and lignification involves interaction of heat shock factors and genes associated with lignin biosynthesis”，论文第一作者为博士生曾教科，李鲜教授为共同第一作者，殷学仁副教授为通讯作者。
枇杷果实采后易发生冷害木质化，本团队近期开始关注果实木质化的转录调控机制，率先发现了参与果实木质化调控的EjMYB1和EjMYB2转录因子(Journal of Experimental Botany, 2014, 65: 4349-4359，陈昆松教授为通讯作者);其后发现了EjAP2-1转录因子作为通过与前期发现的EjMYB1/2发生蛋白互作，进而转录抑制枇杷木质素的生物合成(plant Biotechnology Journal, 2015, 13: 1325-1334，殷学仁副教授为通讯作者)。本研究在前期基础上，进一步发现热激(HT)和程序降温(LTC)处理，可通过HSF转录因子调控枇杷果实木质化，其中EjHSF1响应HT，并通过转录调控热激响应蛋白(Hsp)基因来参与枇杷果实冷害，这是模式植物中常见的调控路径;而EjHSF3受LTC抑制，并可转录抑制木质素合成相关基因EjPAL1、Ej4CL1/5启动子，该调控通路未见报道。进一步研究发现，EjHSF3与EjAP2-1发生蛋白-蛋白互作形成转录因子复合体，进而转录抑制枇杷冷害木质化。
原文链接：
Regulation of loquat fruit low temperature response and lignification involves interaction of heat shock factors and GENEs associated with lignin biosynthesis
原文摘要：
Transcriptional regulatory mechanisms underlying lignin metabolism have been widely studied in model plants and woody trees, as well as fruit, such as loquat (Eriobotrya japonica). Unlike the well-known NAC, MYB and AP2/ERF transcription factors, the roles of heat shock factors (HSFs) in lignin regulation have been rarely reported. Two treatments (heat treatment, HT; low temperature conditioning, LTC) were applied to alleviate low temperature-induced lignification in loquat fruit. Gene expression analysis indicated that EjHSF1 transcript abundance, in parallel with heat shock protein genes (EjHsp), was induced by HT, while expression of EjHSF3 was repressed by LTC. Using dual-luciferase assays, EjHSF1 and EjHSF3 trans-activated the promoters of EjHsp genes and lignin biosynthesis-related genes, respectively. Thus, two distinct regulatory mechanisms of EjHSFtranscription factors in chilling injury-induced fruit lignification are proposed: EjHSF1 transcriptionally regulated EjHsp genes are involved in chilling tolerance, while EjHSF3 transcriptionally regulated lignin biosynthesis. Furthermore, the relations between EjHSF3 and previously characterized fruit lignification regulators, including EjAP2-1, EjMYB1 and EjMYB2, were also investigated. Yeast-two hybrid (Y2H) and biomolecular fluorescence complementation (BiFC) assays demonstrated protein-protein interaction between EjHSF3 and EjAP2-1. Thus, the involvement of EjHSF3 in fruit lignification is via both lignin biosynthetic genes and the regulator,EjAP2-1.
作者：殷学仁
