During two-line hybrid rice seed production, thermo-sensitive genic male sterile (TGMS) rice lines are susceptible to low temperature, leading to fertility alteration (from sterile to fertile) and production of false hybrids (self-pollination). To explore appropriate solutions to reduce the chance of seed production failure, two exogenous substances, d -Arg and ethephon, were applied to restrain the fertility alteration induced by low temperature (22.0 °C), respectively. The fertile pollen grains and bagged seed setting rate of TGMS rice line Jing 4155S (with the critical fertility/sterility alteration temperature of 23.5 °C) under low temperature could be reduced to 0% by spraying exogenous substances. Transcriptome analysis of young panicles of TGMS rice line Jing 4155S demonstrated that the expressions of multiple transcription factors (MYB, FAR1, and ERF, etc.) changed, and hence affecting various downstream related genes and metabolic processes, including hormonal signal transduction, plant pathogen interactions, circadian rhythm pathway, carbohydrate metabolism, cell wall synthesis, and lipid metabolism, etc. The enhanced ethylene biosynthesis and the prevented redox equilibrium from unbalance to balance in young panicles were one of the major reasons that fertility alteration was inhibited by exogenous substances. Our results made a contribution to the solution for inhibiting fertility alteration induced by low temperature in two-line TGMS rice lines during hybrid seed production.

中文翻译：

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比较转录组分析揭示外源物质抑制TGMS水稻品系低温诱导育性改变的机制

在两系杂交水稻种子生产过程中，热敏基因雄性不育 (TGMS) 水稻品系易受低温影响，导致育性改变（从不育变为可育）和产生假杂种（自花授粉）。为了探索减少种子生产失败机会的适当解决方案，分别应用两种外源物质d-Arg和乙烯利来抑制低温（22.0°C）引起的肥力改变。TGMS水稻品系景4155S（育性/不育临界变化温度为23.5℃）在低温下的可育花粉粒和袋装结实率可通过喷洒外源物质降低至0%。TGMS水稻品系京4155S幼穗转录组分析表明，多个转录因子（MYB、FAR1 和 ERF 等）发生变化，从而影响各种下游相关基因和代谢过程，包括激素信号转导、植物病原体相互作用、昼夜节律通路、碳水化合物代谢、细胞壁合成和脂质代谢等。生物合成和防止氧化还原平衡在幼穗中从不平衡到平衡是外源物质抑制生育力改变的主要原因之一。我们的研究结果有助于解决杂交制种过程中两系 TGMS 水稻品系因低温引起的育性变化的抑制问题。糖代谢、细胞壁合成、脂类代谢等。幼穗中乙烯生物合成的增强和氧化还原平衡的失衡是外源性物质抑制生育力改变的主要原因之一。我们的研究结果有助于解决杂交制种过程中两系 TGMS 水稻品系因低温引起的育性变化问题。糖代谢、细胞壁合成、脂类代谢等。幼穗中乙烯生物合成增强和氧化还原平衡不平衡是外源性物质抑制育性改变的主要原因之一。我们的研究结果有助于解决杂交制种过程中两系 TGMS 水稻品系因低温引起的育性变化的抑制问题。