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Resistance to UVB radiation in plant

植物对UVB辐射的抵抗力

基本信息

批准号：
15201010
负责人：
KUMAGAI Tadashi
金额：
$ 29.45万
依托单位：
Tohoku University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (A)
财政年份：
2003
资助国家：
日本
起止时间：
2003 至 2005
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-15201010/
关键词：
ultraviolet-B resistance mechanism cyclobutane pyrimidine dimer photolyase plant rice ion beam QTL analysis イオンブーム耐性機器

项目摘要

1. The difference in UVB sensitivity among rice cultivars is caused by a structure/function alteration of photolyase due to one or two amino acids changes, and the CPD photolyase activity is a crucial factor for determining UVB sensitivity in rice.2. Rice plants with higher CPD photolyase activity by overexpressing CPD photolyase gene showed extremely stronger resistance to UVB-caused growth inhibition, whereas rice plants with lower CPD photolyase activity by insertion of antisense CPD photolyase gene showed extremely higher sensitivity to UVB.3. To clarify the function of rice class II CPD photolyase, effects of alterations of deduced amino acids in CPD photolyase on enzyme activity was investigated using rice CPD photolyase expressed in E.coli. Amino acids Gln296, Ser282 and Ser285 functioned as a FAD binding site. On the other hand, W344 and Y419 worked for binding to neither FAD nor CPD, but play an important role in enzyme activity.4. UV-sensitive mutant (rev3-1) and UV-resistant mutant (uvi4) in Arabidopsis were isolated and characterized. 1)Disrupted mutant of AtREV3, a gene for the putative catalytic subunit of Arabidopsis DNA polymerase ζ, was found to be sensitive to UVB and various DNA-damaging agents. 2)Positional cloning revealed that the uvi4 gene encoded a novel basic protein with unknown function. The hypocotyl cells in uvi4 underwent one extra round of endo-reduplication, and the enhanced polyploidization was responsible for the increased UVB tolerance of the uvi4 mutant.5. Three QTLs associated with UVB resistance on chromosomes 1, 3, and 10, using backcross inbred lines were derived from a cross between an indica cultivar "Kasalath" (UV-sensitive) and a japonica cultivar "Nipponbare" (UV-resistant). Among the QTLs, qUVR-10 for UVB resistance was cloned by map-based strategy. The qUVR-10 contained encoded the CPD photolyase gene.

1．水稻品种间UVB敏感性的差异是由于一两个氨基酸的变化导致光裂合酶结构/功能的改变造成的，而CPD光裂合酶活性是决定水稻UVB敏感性的关键因素。2．通过过表达CPD光裂合酶基因而具有较高CPD光裂合酶活性的水稻植物对UVB引起的生长抑制表现出极强的抗性，而通过插入反义CPD光裂合酶基因而具有较低CPD光裂合酶活性的水稻植物对UVB表现出极高的敏感性。3。为了阐明水稻II类CPD光裂合酶的功能，使用在大肠杆菌中表达的水稻CPD光裂合酶研究了CPD光裂合酶中推导氨基酸的改变对酶活性的影响。氨基酸 Gln296、Ser282 和 Ser285 充当 FAD 结合位点。另一方面，W344和Y419既不与FAD也不与CPD结合，但在酶活性中发挥重要作用。 4．分离并表征了拟南芥中的紫外线敏感突变体 (rev3-1) 和紫外线抗性突变体 (uvi4)。 1) AtREV3 的破坏突变体（拟南芥 DNA 聚合酶 z 的假定催化亚基基因）被发现对 UVB 和各种 DNA 损伤剂敏感。 2)定位克隆表明uvi4基因编码一种功能未知的新型碱性蛋白。 uvi4的下胚轴细胞经历了一轮额外的内复制，增强的多倍体化是uvi4突变体增强UVB耐受性的原因。5．使用回交自交系，从籼稻品种“Kasalath”（紫外线敏感）和粳稻品种“Nipponbare”（紫外线抗性）之间的杂交中获得了 1、3 和 10 号染色体上与 UVB 抗性相关的三个 QTL。在 QTL 中，通过基于图谱的策略克隆了抗 UVB 的 qUVR-10。 qUVR-10包含编码CPD光裂合酶基因。