A novel role for histone methyltransferase KYP/SUVH4 in the control of Arabidopsis primary seed dormancy.

Jian Zheng, Fengying Chen, Zhi Wang, Hong Cao, Xiaoying Li, Xin Deng, Wim J J Soppe, Yong Li, Yongxiu Liu

Index: New Phytol. 193(3) , 605-16, (2012)

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Abstract

• Seed dormancy controls germination and plays a crucial role in the life cycle of plants. Chromatin modifications are involved in the regulation of seed dormancy; however, little is known about the underlying mechanism. • KYP/SUVH4 is required for histone H3 lysine 9 dimethylation. Mutations in this gene cause increased seed dormancy. KYP/SUVH4-overexpressing Arabidopsis plants show decreased dormancy. KYP/SUVH4 expression is regulated by abscisic acid (ABA) and gibberellins (GA). The sensitivity of seed germination to ABA and paclobutrazol (PAC) is enhanced slightly in kryptonite-2 (kyp-2) and suvh4-2/suvh5 mutants, but weakened in KYP/SUVH4-overexpressing plants. • In the kyp-2 mutant, several dormancy-related genes, including DOG1 and ABI3, show increased expression levels, in agreement with a negative role for KYP/SUVH4 in gene transcription. • Genetic analysis showed that DOG1 and HUB1 are epistatic to KYP/SUVH4, suggesting that these genes regulate seed dormancy in the same genetic pathway.© 2011 The Authors. New Phytologist © 2011 New Phytologist Trust.