Rice LTG1 is involved in adaptive growth and fitness under low ambient temperature

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Guangwen Lu, Fu-Qing Wu, Weixun Wu, Hong-Jun Wang, Xiao-Ming Zheng, Yunhui Zhang, Xiuling Chen, Kunneng Zhou, Mingna Jin, Zhijun Cheng, Xueyong Li, Ling Jiang, Haiyang Wang, Jianmin Wan
The Plant Journal, 2014, 78(3): 468-480  DOI: 10.1111/tpj.12487;      追溯原文......本站官方QQ群:62473826
rice (Oryza sativa L.); low ambient temperature; adaptive growth; casein kinase I; functional nucleotide polymorphism

Low temperature (LT) is one of the most prevalent factors limiting the productivity and geographical distribution of rice (Oryza sativa L.). Although significant progress has been made in elucidating the effect of LT on seed germination and reproductive development in rice, the genetic component affecting vegetative growth under LT remains poorly understood. Here, we report that rice cultivars harboring the dominant LTG1 (Low Temperature Growth 1) allele are more tolerant to LT (15–25°C, a temperature range prevalent in high‐altitude, temperate zones and high‐latitude areas), than those with the ltg1 allele. Using a map‐based cloning strategy, we show that LTG1 encodes a casein kinase I. A functional nucleotide polymorphism was identified in the coding region of LTG1, causing a single amino acid substitution (I357K) that is associated with the growth rate, heading date and yield of rice plants grown at LT. We present evidence that LTG1 affects rice growth at LT via an auxin‐dependent process(es). Furthermore, phylogenetic analysis of this locus suggests that the ltg1 haplotype arose before the domestication of rice in tropical climates. Together, our data demonstrate that LTG1 plays an important role in the adaptive growth and fitness of rice cultivars under conditions of low ambient temperature.

LTG1参与水稻低温环境下适应性生长调控

低温(LT)是水稻产量和耕种区域分布的主要限制因素之一。虽然广泛研究了低温对水稻种子萌发和生殖发育的影响,但低温下影响基本营养发育的遗传组分仍知之甚少。本文,我们报道了带有显性LTG1等位基因的水稻品种对于低温环境(15-25°,这个温度范围主要分布在高海拔、温带和高纬度地区)比带有隐性ltg1等位基因的品种具有更好的耐冷性。通过图位克隆手段,我们发现LTG1编码一个酪蛋白激酶I。功能核苷酸多样性分析发现在LTG1编码区,一个单氨基酸替换(I357K)与低温环境下水稻植株的生长速率、抽穗期和产量相关。我们证实LTG1通过生长素依赖途径影响低温下水稻生长。此外,LTG1位点的系统发生分析发现隐性ltg1等位基因的单倍型在热带气候环境水稻驯化之前就已经产生。这些数据证明LTG1在低温度环境条件下影响水稻适应性生长发挥了重要作用。


基因列表
  杂种衰退;酪蛋白激酶 hbd2; OsCKI1; LTG1; LTRPK1