一个 HD-ZIP II 同源盒转录因子 PpHB.G7，在桃果实成熟过程中介导乙烯的生物合成。

A HD-ZIP II HOMEBOX transcription factor, PpHB.G7, mediates ethylene biosynthesis during fruit ripening in peach.

机构信息

College of Horticulture/State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing, 210095, China.

出版信息

Plant Sci. 2019 Jan;278:12-19. doi: 10.1016/j.plantsci.2018.10.008. Epub 2018 Oct 16.

DOI:10.1016/j.plantsci.2018.10.008

PMID:30471725

Abstract

Homeobox transcription factors belong to a superfamily that has been widely studied in plant growth and development, but little is known regarding their role in fruit development and ripening. Using a genome-wide expression analysis of homeobox (HB) genes and quantitative real-time PCR, a HD-ZIP II member, PpHB.G7, which presented higher levels of expression in ripening fruits than in developing fruits in all of the tested cultivars, was isolated from peach. Transient transformations showed that PpHB.G7 affects ethylene production and the expression of ethylene biosynthesis genes (PpACS1 and PpACO1). Both dual-luciferase and yeast one-hybrid assays confirmed that PpHB.G7 interacts with the promoters of PpACS1 and PpACO1. Thus, PpHB.G7 mediates ethylene biosynthesis by stimulating PpACS1 and PpACO1 activities. Furthermore, we also found that the other eight HB genes were differentially expressed in the developing fruits, with seven of these genes belonging to the HD-ZIP family. These results suggest that the HB genes in the HD-ZIP family play important roles in fruit development and ripening.

摘要

同源盒转录因子属于一个超家族，该超家族在植物生长和发育中已得到广泛研究，但对于其在果实发育和成熟中的作用知之甚少。本研究通过对同源盒（HB）基因的全基因组表达分析和定量实时 PCR，从桃中分离出一个在所有测试品种的成熟果实中表达水平均高于发育果实的 HD-ZIP II 成员 PpHB.G7。瞬时转化表明，PpHB.G7 影响乙烯的产生和乙烯生物合成基因（PpACS1 和 PpACO1）的表达。双荧光素酶和酵母单杂交实验均证实 PpHB.G7 与 PpACS1 和 PpACO1 的启动子相互作用。因此，PpHB.G7 通过刺激 PpACS1 和 PpACO1 的活性来介导乙烯的生物合成。此外，我们还发现其他 8 个 HB 基因在发育果实中差异表达，其中 7 个基因属于 HD-ZIP 家族。这些结果表明，HD-ZIP 家族中的 HB 基因在果实发育和成熟中发挥重要作用。