The MKK3 MAPK cascade integrates temperature and after- ripening signals to modulate seed germination

• 成果类型: Article
• 署名作者: Otani, Masahiko; Tojo, Ryo; Regnard, Sarah; Zheng, Lipeng; Hoshi, Takumi; Ohmori, Suzuha; Tachibana, Natsuki; Sano, Tomohiro; Koshimizu, Shizuka; Ichimura, Kazuya; Colcombet, Jean; Kawakami, Naoto; Shinozaki, Kazuo
• 署名单位: Meiji University; Meiji University; Universite Paris Saclay; Universite Paris Cite; Centre National de la Recherche Scientifique (CNRS); Chinese Academy of Sciences; University of Science & Technology of China, CAS; Research Organization of Information & Systems (ROIS); National Institute of Genetics (NIG) - Japan; Kagawa University
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-13927
• DOI: 10.1073/pnas.2404887121
• 发表日期: 2024-07-09
• 关键词: protein-kinase cascades; abscisic-acid; arabidopsis-thaliana; gibberellin biosynthesis; dormancy; expression; genes; thermoinhibition; 8'-hydroxylases; metabolism

摘要

The timing of seed germination is controlled by the combination of internal dormancy and external factors. Temperature is a major environmental factor for seed germination. The permissive temperature range for germination is narrow in dormant seeds and expands during after- ripening (AR) (dormancy release). Quantitative trait loci analyses of preharvest sprouting in cereals have revealed that MKK3, a mitogen- activated protein kinase (MAPK) cascade protein, is a negative regulator of grain dormancy. Here, we show that the MAPKKK19/20- MKK3- MPK1/2/7/14 cascade modulates the germination temperature range in Arabidopsis seeds by elevating the germinability the seeds at sub- and supraoptimal temperatures. The expression of MAPKKK79 and MAPKKK20 is induced around optimal temperature for germination in after- ripened seeds but repressed in dormant seeds. MPK7 activation depends on the expression levels of MAPKKK79/20 , with expression occurring under conditions permissive for germination. Abscisic acid (ABA) and gibberellin (GA) are two major phytohormones which are involved in germination control. Activation of the MKK3 cascade represses ABA biosynthesis enzyme gene expression and induces expression of ABA catabolic enzyme and GA biosynthesis enzyme genes, resulting in expansion of the germinable temperature range. Our data demonstrate that the MKK3 cascade integrates temperature and AR signals to phytohormone metabolism and seed germination.