Yang Xuedong, Zhang Xuelian, Yang Youxin, Zhang Hui, Zhu Weimin, Nie Wen-Feng
Shanghai Key Laboratory of Protected Horticultural Technology, Horticulture Research Institute, Shanghai Academy of Agricultural Sciences, 201403, Shanghai, China.
Department of Horticulture, College of Agronomy, Jiangxi Agricultural University, 330045, Nanchang, Jiangxi, China.
Hortic Res. 2021 Apr 1;8(1):85. doi: 10.1038/s41438-021-00520-3.
The conserved histone variant H2A.Z is essential for transcriptional regulation; defense responses; and various biological processes in plants, such as growth, development, and flowering. However, little is known about how H2A.Z affects the developmental process and ripening of tomato fruits. Here, we utilized the CRISPR/Cas9 gene-editing system to generate a sl_hta9 sl_hta11 double-mutant, designated sl_h2a.z, and found that these two mutations led to a significant reduction in the fresh weight of tomato fruits. Subsequent messenger RNA (mRNA)-seq results showed that dysfunction of Sl_H2A.Z has profound effects on the reprogramming of genome-wide gene expression at different developmental stages of tomato fruits, indicating a ripening-dependent correlation between Sl_H2A.Z and gene expression regulation in tomato fruits. In addition, the expression of three genes, SlPSY1, SlPDS, and SlVDE, encoding the key enzymes in the biosynthesis pathway of carotenoids, was significantly upregulated in the later ripening stages, which was consistent with the increased contents of carotenoids in sl_h2a.z double-mutant fruits. Overall, our study reveals a role of Sl_H2A.Z in the regulation of carotenoids and provides a resource for the study of Sl_H2A.Z-dependent gene expression regulation. Hence, our results provide a link between epigenetic regulation via histone variants and fruit development, suggesting a conceptual framework to understand how histone variants regulate tomato fruit quality.
保守的组蛋白变体H2A.Z对于转录调控、防御反应以及植物中的各种生物学过程（如生长、发育和开花）至关重要。然而，关于H2A.Z如何影响番茄果实的发育过程和成熟，人们知之甚少。在这里，我们利用CRISPR/Cas9基因编辑系统构建了一个名为sl_h2a.z的sl_hta9 sl_hta11双突变体，发现这两个突变导致番茄果实鲜重显著降低。随后的信使核糖核酸（mRNA）测序结果表明，Sl_H2A.Z功能障碍对番茄果实不同发育阶段全基因组基因表达的重编程有深远影响，这表明Sl_H2A.Z与番茄果实基因表达调控之间存在成熟依赖性关联。此外，编码类胡萝卜素生物合成途径中关键酶的三个基因SlPSY1、SlPDS和SlVDE的表达在成熟后期显著上调，这与sl_h2a.z双突变体果实中类胡萝卜素含量的增加一致。总体而言，我们的研究揭示了Sl_H2A.Z在类胡萝卜素调控中的作用，并为研究Sl_H2A.Z依赖性基因表达调控提供了资源。因此，我们的结果在通过组蛋白变体的表观遗传调控与果实发育之间建立了联系，为理解组蛋白变体如何调控番茄果实品质提供了一个概念框架。
