Chen Min, Fu Yuying, Mou Qingshan, An Jianyu, Zhu Xiaobo, Ahmed Temoor, Zhang Sheng, Basit Farwa, Hu Jin, Guan Yajing
Institute of Crop Sciences, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou 310058, China.
Institute of Horticulture, Anhui Academy of Agricultural Sciences, Hefei 230041, China.
Antioxidants (Basel). 2021 Sep 28;10(10):1544. doi: 10.3390/antiox10101544.
Heat stress during seed maturation significantly reduced seed size and quality. Polyamines, especially spermidine (Spd), were reported to be closely related to seed development and plant heat tolerance. Stress-associated proteins (SAPs) also played a critical role in plant heat resistance, but the relationship between Spd and SAPs in improving rice tolerance to heat stress during grain filling has not been reported. Our results showed that the external spraying Spd (1.5 mM) significantly increased seed germination rate, germination index, vigor index and 1000-grain weight, significantly increased endogenous Spd, spermine (Spm) content and peroxidase activity; significantly reduced MDA content; and greatly alleviated the impact of heat stress on rice seed quality during grain filling stage as compared with high temperature control. was the most upregulated expression induced by Spd, and may be mainly involved in the Spd-mediated enhancement of high-temperature resistance during rice seed development. Overexpression of in enhanced 1000-grain weight and seed heat resistance. Exogenous Spd alleviated the survival rate and seedling length, reduced MDA content, and upregulated the expression levels of and in mutant under high temperature during seed germination. In all, exogenous Spd alleviated the heat damage on seed quality during the grain filling stage and seed germination stage by improving endogenous Spd and Spm. , a key gene induced by Spd, might be involved in the rice heat resistance and seed quality in coordination with Spd and Spm.
种子成熟期间的热胁迫显著降低了种子大小和质量。据报道，多胺，尤其是亚精胺（Spd）与种子发育和植物耐热性密切相关。胁迫相关蛋白（SAPs）在植物耐热性中也起着关键作用，但在灌浆期Spd与SAPs在提高水稻耐热胁迫能力方面的关系尚未见报道。我们的结果表明，外源喷施Spd（1.5 mM）显著提高了种子发芽率、发芽指数、活力指数和千粒重，显著提高了内源Spd、精胺（Spm）含量和过氧化物酶活性；显著降低了丙二醛含量；与高温对照相比，在灌浆期极大地减轻了热胁迫对水稻种子质量的影响。 是Spd诱导上调表达最高的基因，可能主要参与了水稻种子发育过程中Spd介导的耐热性增强。在 中过表达 提高了千粒重和种子耐热性。外源Spd在种子萌发期高温条件下提高了 突变体的成活率和幼苗长度，降低了丙二醛含量，并上调了 和 的表达水平。总之，外源Spd通过提高内源Spd和Spm减轻了灌浆期和种子萌发期热胁迫对种子质量的损害。Spd诱导的关键基因 可能与Spd和Spm协同参与水稻耐热性和种子质量调控。
