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Resistance of rice to ultraviolet-B radiation based on UVB-induced DNA lesions and their photorepairs

基于 UVB 诱导的 DNA 损伤及其光修复的水稻对 UV-B 辐射的抵抗力

基本信息

批准号：
10044195
负责人：
KUMAGAI Tadashi
金额：
$ 6.27万
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：
1998
资助国家：
日本
起止时间：
1998 至 1999
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10044195/
关键词：
UVB radiation DNA lesion Cyclobutyl pyrimidine dimer photolyase Photorepair Rice Resistance to UVB Sensitivity to UVB ミクロブタン型ピリミジンダイアー光修復酵素

项目摘要

1 Changes in DNA lesions during growth in rice: (1) We found that rice could be more susceptible to CPD induction at the stage when the second, third or fourth leaves are developing, and UVB sensitivity correlates with low CPD photorepair. (2) Dark-grown etiolated rice does not have any CPD photorepair ability, and the induction of CPD photorepair was shown to be controlled by phytochrome/cryptochrome photosystems. (3) It was evident that 2-3 CPDs/Mb. DNA is always being kept in rice growing in solar radiation.2 Cultivar differences in CPD photorepair between UV-resistant and -sensitive rice : We previously suggested that two possibilities might account for CPD photorepair defiviency in UV-sensitive rice (Norin 1). One is due to a structural mutation, which could affect the formation of CPD-photolyase complex, or dissociation of the complex. The other is due to mutation of regulatory mechanisms for induction of photolyase, which could decrease the levels of photolyase. Based on the single light-pulse method and temperature dependence, we have proved that a structural mutation might be involved in high UV-sensitivity in Norin 1.3 Effect of UVB radiation on protein contents in leaves : We previously suggested that Rubisco rather than LHCII might be more influenced by supplemental UVB radiation during growth. Therefore, we studied the effects of UVB radiation (1) on the synthesis and degradation of Rubisco and LHCII using ィイD115ィエD1N as a tracer, and (2) on the mRNA transcript levels for Rubisco subunits (rbcS encoded in nuclear and rbcL encoded in chloroplast) and LHCII (cab encoded in nuclear, in leaves of UV-resistant and -sensitive rice. We found that the expression of nuclear encoded genes were more influenced than that of chloroplast by UVB, and that the expression of rbcL was more influenced than cab by UVB.

1水稻生长过程中DNA损伤的变化：（1）发现水稻在第2、3、4叶发育期对CPD诱导更敏感，UVB敏感性与低CPD光修复相关。(2)暗生长黄化水稻没有任何CPD光修复能力，CPD光修复的诱导被证明是由光敏色素/隐花色素光系统控制。(3)很明显，2-3 CPD/Mb。2.抗紫外线水稻和紫外线敏感水稻CPD光修复的品种差异：我们以前认为，两种可能性可能是紫外线敏感水稻（Norin 1）CPD光修复缺陷的原因。一种是由于结构突变，这可能会影响CPD-光解酶复合物的形成或复合物的解离。另一种是由于诱导光裂合酶的调控机制发生突变，导致光裂合酶水平降低。基于单光脉冲方法和温度依赖性，我们已经证明了结构突变可能涉及高UV敏感性的Norin 1.3 UVB辐射对叶片中蛋白质含量的影响：我们以前建议Rubisco而不是LHCII可能更多地受到生长过程中补充UVB辐射的影响。因此，我们研究了UVB辐射对水稻叶片中Rubisco和LHC Ⅱ合成和降解的影响，并以UVB D115为示踪剂，研究了UVB辐射对水稻叶片Rubisco亚基（rbcS编码于核中，rbcL编码于叶绿体中）和LHC Ⅱ（cab编码于核中）mRNA转录水平的影响。结果表明，UVB对核基因表达的影响大于叶绿体基因，对rbcL基因表达的影响大于cab基因。