摘要
目的:探讨低剂量(≤30 Gy)电离辐射对甘蓝型油菜(简称油菜)幼苗期抗氧化酶活性及光合作用的影响。方法:采用土培方式获得油菜幼苗,每个剂量组包括5棵油菜。以^(137)Cs为放射源,采用间隔照射代替慢性照射,每周照射5 d,每天照射7 h,照射剂量率为8.28 mGy/min,总照射剂量分别为0(对照组)、5、10、15、20、25和30 Gy组。检测受照后幼苗超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、过氧化物酶(POD)活性,叶片叶绿素a、b、a+b、类胡萝卜素含量,采用实时荧光定量PCR检测光合作用相关基因(psb A、psb D、psb C和LOD106434505)的表达。结果:与对照组比较,SOD活性随着照射剂量的增加而增强(P<0.05);CAT活性在30 Gy照射组最高且增加至对照组的1.50倍(P<0.05);POD活性在5和15 Gy照射组表现为增加(P<0.05),25 Gy剂量组最低,仅为对照组的41%(P<0.05)。随着照射剂量的增加,油菜幼苗的叶绿素a、b含量先增加,在10 Gy剂量组最高(P<0.05),随后降低;叶绿素a+b含量和类胡萝卜素含量变化不显著,在5 Gy剂量组最高(P<0.05)。油菜受到照射后,psb A和psb D mRNA的表达变化不明显(P>0.05);psb C mRNA的表达水平除15 Gy剂量组外均下调(P<0.05);LOC106434505 mRNA的表达随着照射剂量增加的显著上调(P<0.05)。结论:低剂量(≤30 Gy)^(137)Cs照射能够增强油菜幼苗抗氧化酶活性,并通过影响油菜幼苗叶绿素含量、光电子转运、能量捕获与传递对油菜光合作用产生影响。
OBJECTIVE:To investigate effects of low dose(≤30 Gy)ionizing radiation on antioxidant enzyme and photosynthesis activities in Brassica napus L.(B.napus)seedlings.METHODS:B.napus seedlings were obtained through soil culture,with each dose group consisted of 5 rapeseed plants.Intermittent ^(137)Cs irradiation instead of chronic irradiation was used.The irradiation was conducted 5 days per week for 7 hours per day at doses of 0(control group),5,10,15,20,25,and 30 Gy,with an irradiation dose rate of 8.28 mGy/min.The activities of superoxide dismutase(SOD),catalase(CAT),peroxidase(POD),content of chlorophyll a,b,a+b,carotenoid in leaves,and expression of genes related to photosynthesis(psb A,psb D,psb C,and LOD106434505)in the leaves of the seedlings after irradiation were detected and analyzed.RESULTS:Compared with the control group,the activities of SOD and CAT increased with the increase of irradiation dose(P<0.05),but there is no significant trend in POD activity(P>0.05).As the irradiation dose increased,the chlorophyll a and b contents of the seedlings first increased,reaching the highest in the 10 Gy dose group(P<0.05),and then decreased.There was no significant trend in changes in chlorophyll a+b content and carotenoid content,with the highest in the 5 Gy dose group(P<0.05).After irradiation,the expression level of gene psb C was downregulated(except for the 15 Gy dose group,P<0.05).The expression of LOC106434505 was significantly upregulated with increasing irradiation(P<0.05),while the expression changes of psb A and psb D were not significant.CONCLUSION:Low dose(≤30 Gy)^(137)Cs irradiation enhanced the antioxidant enzyme activities of rapeseed seedlings,and affected photosynthesis by perturbing chlorophyll content,photoelectron transport,and energy capture and transfer.
作者
李斌
闫冬
范莉
姜晓燕
LI Bin;YAN Dong;FAN Li;JIANG Xiaoyan(National Institute for Radiological Protection,Chinese Center for Disease Control and Prevention,Beijing 100088,China)
出处
《癌变．畸变．突变》
CAS
2023年第6期420-425,共6页
Carcinogenesis,Teratogenesis & Mutagenesis
