摘要
研究了0·4W/m2UV-B辐射和0·4%NaCl胁迫对两绿豆品种中绿_1和秦豆-20(PhaseolusraditusL.cv.Zhongl櫣-1andQindou-20)幼苗叶片DNA损伤的复合效应。结果表明:(1)中绿-1抗UV-B辐射和NaCl胁迫的能力均强于秦豆-20;NaCl胁迫能降低中绿-1UV-B敏感性,但对秦豆-20UV-B敏感性无明显影响。(2)两逆境因子单独胁迫或复合胁迫下DNA增色效应均明显降低,但中绿-1降低程度小于秦豆-20,复合胁迫下降低程度小于单独NaCl胁迫下。(3)UV-B辐射诱导的中绿-1DNA链内环丁烷嘧啶二聚体(CPD)累积量明显低于秦豆-20;NaCl胁迫能降低UV-B诱导的中绿-1CPD累积,而对UV-B诱导的秦豆-20CPD累积无影响。(4)各种胁迫处理均导致两品种幼苗DNA含量降低,但两品种间相比中绿-1降低程度较大。结果说明UV-B辐射不仅能诱导DNA链内交联形成CPD,而且能诱导DNA链间交联和DNA含量降低,且不同绿豆品种或同一品种在有无NaCl胁迫时UV-B敏感性的差异主要与CPD累积量和DNA链间交联程度有关。
The interactive effect of 0.4 W/m^2 UV-B radiation and 0.4% NaCl stress on DNA in the primary leaves of two mung bean cuhivars （ Phaseolus raditus L. cv. Zbonglü-1 and Qindou-20） was studied. The results showed that （1） mung bean cuhivar ＂Zhonglü-1＂ is more tolerant to both UV-B radiation and NaCl stress than cuhivar ＂Qindou-20＂. NaCl stress reduced UV-B sensitivity of ＂Zhonglü-1＂, but did not change UV-B sensitivity of ＂Qindou-20＂. （2） Treatment of the two cultivars by either UV-B or NaCl alone or by both stresses together resulted in a decrease in DNA hyperchromicity in the two mung bean cuhivars. The extent of the decrease in cultivar ＂Zhonglü-1＂ was lower than that in cuhivar ＂Qindou-20＂. Decrease in DNA hyperchromicity in the two mung bean cuhivars under both UV-B and NaCl stresses together was lower than that under NaCl stress alone, （3） UV-Binduced cyclobutyl pyrimidine dimers （CPD） accumulation in cultivar ＂Zhonglü-1＂ was lower than that in cuhivar ＂Qindou-20＂ ; NaCl stress could reduce the UV-B-induced CPD accumulation in cuhivar ＂Zhonglü-1＂, but did not change that in cuhivar ＂Qindou-20＂. （4） All stress treatments caused a drop of DNA content in two mung bean cultivars but with cuhivar ＂Zhonglü-1＂ showing stronger responses. These results indicate that UV-B radiation can induce not only the formation of CPD on the same DNA strand, but also the formation of cross-linking between the two strands of DNA and the decrease in DNA content. It is also suggested that the different UV-B sensitivity between two mung bean cultivars under either NaCl stress or no NaCl stress might be mainly caused by the differences in CPD accumulation and cross-linking between the two strands of DNA.
出处
《生态学报》
CAS
CSCD
北大核心
2006年第5期1375-1381,共7页
Acta Ecologica Sinica
基金
陕西省自然科学基金资助项目(2003C101)
国家自然科学基金资助项目(30470324)~~
关键词
UV-B辐射
NACL胁迫
绿豆幼苗
DNA链间交联
环丁烷嘧啶二聚体累积
UV-B radiation
NaCl stress
mung bean seedlings
cross-linking between two strands of DNA
cyclobutyl pyfimidine dimers （CPD） accumulation
