Heilongjiang Academy of Agricultural Sciences Postdoctoral Programme, Harbin, 150086, Heilongjiang, China; Maize Research Institute of Heilongjiang Academy of Agricultural Sciences, Nangrang, Harbin, Heilongjiang, China.
Maize Research Institute of Heilongjiang Academy of Agricultural Sciences, Nangrang, Harbin, Heilongjiang, China.
Genomics. 2021 Mar;113(2):782-794. doi: 10.1016/j.ygeno.2021.01.018. Epub 2021 Jan 28.
Maize (Zea mays L.) is a thermophilic plant and a minor drop in temperature can prolong the maturity period. Plants respond to cold stress through structural and functional modification in cell membranes as well as changes in the photosynthesis and energy metabolism. In order to understand the molecular mechanisms underlying cold tolerance and adaptation, we employed leaf transcriptome sequencing together with leaf microstructure and relative electrical conductivity measurements in two maize inbred lines, having different cold stress tolerance potentials. The leaf physiological and transcriptomic responses of maize seedlings were studied after growing both inbred lines at 5 °C for 0, 12 and 24 h. Differentially expressed genes were enriched in photosynthesis antenna proteins, MAPK signaling pathway, plant hormone signal transduction, circadian rhythm, secondary metabolites related pathways, ribosome, and proteasome. The seedlings of both genotypes employed common stress responsive pathways to respond to cold stress. However, the cold tolerant line B144 protected its photosystem II from photooxidation by upregulating D1 proteins. The sensitive line Q319 was unable to close its stomata. Collectively, B144 exhibited a cold tolerance owing to its ability to mediate changes in stomata opening as well as protecting photosystem. These results increase our understanding on the cold stress tolerance in maize seedlings and propose multiple key regulators of stress responses such as modifications in photosystem II, stomata guard cell opening and closing, changes in secondary metabolite biosynthesis, and circadian rhythm. This study also presents the signal transduction related changes in MAPK and phytohormone signaling pathways in response to cold stress during seedling stage of maize.
玉米（Zea mays L.）是一种喜温植物，温度稍有下降会延长其成熟周期。植物通过细胞膜的结构和功能改变以及光合作用和能量代谢的变化来应对冷应激。为了了解耐寒性和适应性的分子机制，我们采用叶片转录组测序以及叶片微观结构和相对电导率测量，研究了两个玉米自交系在不同耐冷胁迫潜力下的冷胁迫响应。在将两个自交系分别在 5°C 下生长 0、12 和 24 h 后，研究了玉米幼苗的叶片生理和转录组响应。差异表达基因富集在光合作用天线蛋白、MAPK 信号通路、植物激素信号转导、昼夜节律、次生代谢物相关途径、核糖体和蛋白酶体。两种基因型的幼苗都采用了共同的应激响应途径来应对冷应激。然而，耐寒型 B144 通过上调 D1 蛋白来保护其光系统 II 免受光氧化。敏感型 Q319 无法关闭其气孔。总的来说，B144 表现出耐寒性，因为它能够调节气孔的开闭以及保护光系统。这些结果增加了我们对玉米幼苗冷胁迫耐受性的理解，并提出了多个关键的应激响应调节剂，如光系统 II 的改变、气孔保卫细胞的开闭、次生代谢物生物合成的变化和昼夜节律。本研究还揭示了玉米幼苗阶段 MAPK 和植物激素信号通路在冷应激下的信号转导相关变化。
