Acta Agriculturae Zhejiangensis ›› 2022, Vol. 34 ›› Issue (6): 1103-1113.DOI: 10.3969/j.issn.1004-1524.2022.06.01

• Crop Science • Previous Articles     Next Articles

Dynamic profile of genes related to seed dormancy under high humidity condition during late stage of rice grain filling

DONG Yuanyuan1,2(), XU Heng2, ZHANG Hua2, ZHANG Heng2, WANG Fulin2, GU Nana2, ZHU Ying2,*()   

  1. 1. College of Chemistry and Life Sciences, Zhejiang Normal University, Jinhua 321004, Zhejiang, China
    2. State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-Products, Institute of Virology and Biotechnology, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China
  • Received:2022-02-22 Online:2022-06-25 Published:2022-06-30
  • Contact: ZHU Ying

Abstract:

To investigate the effect of high humidity on pre-harvest sprouting in the late stage of rice grain filling, milky stage rice plants, at 26, 28, 30, 32 DAP (day after pollination) respectively, were undergo high humidity treatment in the artificial climate chamber (28 ℃/22 ℃, 12 h light/12 h dark cycle, relative humidity were 60%, photosynthetic photon flux density were 600 μmol·m-2·s-1). Spikelet was sprayed periodically by water (spray 500 mL water once every 3 h per bots, 5 d in total) to mimic continuous rainy conditions, and the viviparity of mature seeds were then investigated. Then, developing seeds at DAP30 were undergo same treatment and the dynamic expression of ABA and GA synthesis and metabolism and α-starch hydrolase and other related genes were investigated at different time under high humidity treatment. The results indicated that seed maturity was an important factor affecting viviparity induced by high humidity. Few seeds were sprouted at DAP26 and DAP28 but most of seeds could be sprouted after DAP30 under high humidity treatments. The results showed that high humidity treatment could rapidly induce the expression of abscisic acid (ABA) degradation related genes, such as OsABA8ox1 and OsABA8ox3, and gibberellin (GA) synthesis genes such as OsGA3ox2 and OsGA20ox1, and simultaneously inhibited the expression of key ABA synthesis genes OsNECD1, OsNECD2 and OsNECD3. Many α-starch hydrolase genes, such as OsAmy1A, OsAmy3B, OsAmy3C and OsAmy3D were activated after 72 h water-spraying treatment and provided material and energy for seed germination. The results of this study would help us to understand the molecular mechanism of pre-harvest sprouting under rainy climate.

Key words: high humidity, pre-harvest spouting, rice, gene expression

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