外源H_(2)O_(2)对甘蓝型油菜生长发育的影响

Effects of Exogenous H_(2)O_(2) on the Growth and Development of Brassica napus L.

目的:探讨外源H_(2)O_(2)对甘蓝型油菜种子萌发及幼苗生长发育的影响。方法:本研究采用不同浓度(0.0%、0.1%、0.6%、1.3%和2.1%)H_(2)O_(2)处理甘蓝型油菜‘16VHNTS309’并测定植物体内活性氧(ROS)含量及过氧化氢酶(CAT)、超氧化粉歧化酶(SOD)和过氧化物酶(POD)活性。结果:研究结果表明不同浓度外源H_(2)O_(2)对甘蓝型油菜种子萌发和生长发育影响显著(P<0.05),且甘蓝型油菜种子的发芽率和根系长度随着H_(2)O_(2)浓度的增加呈先升高后降的趋势,在0.6%H_(2)O_(2)处理时种子发芽率达到最高,为95.33%;0.1%H_(2)O_(2)处理时根系长度最长,为3.20 cm。为进一步验证H_(2)O_(2)对甘蓝型油菜生长发育的影响,本研究对正常生长4 d后的幼苗喷施H_(2)O_(2),研究发现0.1%H_(2)O_(2)处理时根系长度最长达到6.99 cm,而高浓度的H_(2)O_(2)则导致根系变短且根毛增多。研究也发现随着H_(2)O_(2)浓度的增加,内源H_(2)O_(2)和O_(2)^(-),呈递增的趋势,而甘蓝型油菜油菜幼苗体内抗氧化酶活性(CAT、SOD和POD)呈递减的趋势。结论:综上研究进一步说明,低浓度的外源H_(2)O_(2)促进甘蓝型油菜种子发芽及根系生长,而高浓度的H_(2)O_(2)导致植物体内的抗氧化酶(CAT、SOD和POD)活性降低、细胞内的ROS含量增多,进而抑制了甘蓝型油菜种子发芽及根系生长。

Objective:To study the effects of exogenous H_(2)O_(2) on seed germination and growth of Brassica napus.Methods:‘16VHNTS309’was treated with different concentrations of H_(2)O_(2)(0.0%,0.1%,0.6%,1.3% and 2.1%),and the contents of reacive oxygen species(ROS)and the activities of catalase(CAT),superoxide dismutase(SOD)and peroxidase(POD)in the plants were determined.Results:The results showed that different concentrations of exogenous H_(2)O_(2) had significant effects on seed germination and growth of B.napus(P<0.05).The seed germination rate and root length of B.napus seedlings increased at first and then decreased with the increase of H_(2)O_(2) concentration,and reached the highest at 0.6%H_(2)O_(2) treatment with 95.33%.The longest root length was 3.20 cm when treated with 0.1%H_(2)O_(2).In order to further verify the effect of H_(2)O_(2) on the growth and development of B.napus,the seedlings were sprayed with H_(2)O_(2) after 4 days of normal growth.It was found that the longest root length reached 6.99 cm when treated with 0.1%H_(2)O_(2),while high concentration of H_(2)O_(2) resulted in shorter roots and more root hairs.The results also showed that with the increase of H_(2)O_(2) concentration,the endogenous H_(2)O_(2) and O_(2)-increased.The antioxidant enzyme(CAT,SOD and POD)activities decreased with the increase of H_(2)O_(2) concentration.Conclusion:Low concentration of exogenous H_(2)O_(2) promoted seed germination and root growth of B.napus,while high concentration of H_(2)O_(2) reduced the activities of antioxidant enzymes(CAT,SOD and POD)and increased intracellular ROS content in plants,which in turn inhibited seed germination and root growth of B.napus.