Protein Kinase LTRPK1 Influences Cold Adaptation and Microtubule Stability in Rice

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Wei Liu, Shuxia Ji, Xiaoliang Fang, Qingguo Wang, Zhen Li, Fangyin Yao, Lei Hou, Shaojun Dai
Journal of Plant Growth Regulation, 2013, 32(3): 483-490  DOI: 10.1007/s00344-012-9314-4;      追溯原文......本站官方QQ群:62473826
LTRPK1; Rice (Oryza sativa L); Casein kinase; Cold stress; Microtubule stability; Rice breeding; Germplasm innovation

Rice LTRPK1, which encodes a member of the casein kinase I family, has been reported to be involved in root development, hormone response, and metabolic processes. Here we further show that LTRPK1 participates in stress resistance by regulating cytoskeleton rearrangement and formation of cold tolerance and adaptation. Semiquantitative RT-PCR analysis revealed enhanced expression of LTRPK1 in plants subject to low-temperature stress at 4 °C, suggesting a role in low-temperature-related cell responses and signal transduction pathways. Further analysis of LTRPK1-deficient transgenic plants showed that under low-temperature treatment, the growth rate of transgenic plant primary roots, which is commonly used as an indicator for cold stress response abilities, was less inhibited than that of control plants. Moreover, damage to the plasma membrane of root cells in LTRPK1-deficient plants was greater than that of controls as measured by relative electrical conductivity (REC). The malondialdehyde (MDA) content of LTRPK1-deficient plants also increased over that of the control, indicating increased plasma membrane permeability. Further immunofluorescence localization observations indicated that microtubules of transgenic plants subject to low temperature disassembled more rapidly, whereas the control plant microtubules in most cells of the root elongation zone kept their normal habitus, which suggested that LTRPK1-deficient plants had reduced capacity to resist low-temperature stress through regulation of microtubule assembly. These results demonstrate involvement of LTRPK1 in low-temperature stress and provide new insight for rice breeding and germplasm innovation to improve crop cold tolerance.

蛋白激酶LTRPK1影响水稻冷适应和微管稳定性

水稻LTRPK1编码酪蛋白激酶I家族的成员,曾被报道参与根发育、激素响应和代谢过程。本文我们进一步发现LTRPK1通过调节细胞骨架重排、建立耐冷性和冷适应,参与抗逆。半定量RT—PCR分析发现,4℃低温胁迫下植株中LTRPK1表达水平增加,表明LTRPK1在低温相关的细胞响应和信号转导通路中发挥作用。分析LTRPK1缺陷型转基因植株表明,低温处理下,转基因植株初生根的生长速率受抑制的程度比对照植株少,而初生根的生长速率通常作为冷胁迫响应能力的指标。此外,通过测定相对电导率(REC)发现,LTRPK1缺陷植株的根细胞质膜损伤程度大于对照。LTRPK1缺陷植株的丙二醛(MDA)含量也比对照增加的多,表明质膜通透性增加。免疫荧光定位结果表明,低温情况下转基因植物的微管更快地解聚,而对照植株根部伸长区大部分细胞中微管保持正常状态,这表明LTRPK1缺陷植株调节微管组装的能力降低,导致抵抗低温能力降低。以上结果表明LTRPK1参与调节低温胁迫耐受性,并为通过水稻育种和种质创新,提高作物耐冷性提供了新思路。


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