Fluctuation of Ethylene Production in Excised Panicles and Flag Leaf Blades during Grain Ripening in Rice (Oryza sativa L.)

Japanese Journal of Crop Science

Hitoshi SAKA¹  Shinichiro WATANABE¹  Akio KOGEN¹  Minoru OKUMURA¹ 

关键词: Ethylene production;    イネ;    Flag leaf blade;    エチレン生成;    Milk-ripe stage;    植物生長調節剤;    Oryza sativa L.;    止葉葉身;    Panicle;    乳熟期;    Plant growth regulator;    光効果;    Rice;    ç©‚;   

DOI  :  10.1626/jcs.61.285

学科分类：农业科学（综合）

来源: Nihon Sakumotsu Gakkai / Crop Science Society of Japan

【 摘 要 】

Ethylene production and its fluctuation in panicles and flag leaf blades in the rice plant (Oryza sativa L.) during the grain ripening stage were examined. The effect of plant growth regulators (growth retardants and brassinosteroids) on fluctuating ethylene production in rice panicles were also investigated. The results are summarized as follows: (1) Ethylene production was readily determined by excising and incubating 2 to 3 panicles and flag leaf blades of rice for 24 h in a test tube stoppered with a serum cap. Under these conditions, ethylene production in ripening panicles increased significantly when exposed to light (about 30 μE·m-2·sec-1) as compared to conditions of darkness. However, light exposure reduced ethylene production below the levels achieved in darkness in flag leaf blades in contrast to the results with panicles. (2) Light-stimulated ethylene production in the panicle fluctuated during grain ripening, reaching its maximum rate of production at the milk-ripe stage. Lower rates were observed before and after the milk-ripe stage. (3) A high rate of ethylene production was maintained in the flag leaf blade until the milk-ripe stage, followed by a rapid decrease in subsequent stages. (4) In greenhouse experiments, the application of plant growth retardants (paclobutrazol and GRH-624) and brassinosteroids (brassinolide and epibrassinolide) several days prior to heading resulted in increased panicle fresh weight with concomitant increases in ethylene production as compared to control at the milk-ripe stage. The data suggest that light-dependent ethylene production in rice panicles is related to the different maturation stages following anthesis and fertilization in the rice plant.

【 授权许可】

Unknown