摘要
从20个水稻品种中筛选出较耐亚铁的水稻品种协优9308和敏感品种IR64,采用静置培养(使边缘细胞附于根尖)和摇床培养(移除根尖边缘细胞),测定根相对伸长率、含水量、根尖保护酶(POD、SOD、CAT)活性以及各根段铁含量,研究边缘细胞对水稻根尖铁胁迫的缓解效应。结果表明,铁毒处理抑制根的伸长、降低幼根的含水量,移除边缘细胞的根相对伸长率以及含水量都低于保留边缘细胞的根,且随着铁毒处理时间的增加,根相对伸长率和幼根的含水量总体呈现下降趋势。在200 mg/L铁毒处理下,根尖保护酶(POD、SOD、CAT)活性受到抑制(除静置培养下协优9308的POD活性外),摇床培养对酶活性的抑制程度较大。铁毒处理使根段铁含量显著上升,静置培养下根段铁含量从0～2 mm到8～10 mm依次增大,摇床培养除8～10 mm根段外其余均无显著差异。说明边缘细胞在水稻根尖铁毒防御中起着一定的作用。
A Fe^2＋ tolerant rice variety （Xieyou 9308） and a Fe^2＋ sensitive variety （IR64） screened from 20 rice varieties were used to study the function of border cells in alleviating ferrous toxicity in rice root tips. The relative elongation rates, water content, activities of peroxidase （POD）, superoxide dismutase （SOD）, catalase （CAT） and content of Fe in rice root were measured at 0 （CK） and 200 μmol/L Fe^2＋ for 6 h, 12 h and 24 h respectively, under static culture （to maintain border cells adhered to the root tips） and shaking culture （to remove border cells from root tips completely）. The results showed that the relative elongation rates and water content of rice root were reduced by ferrous iron, especially under shaking culture. With the increase of Fe^2＋ treatment time, the relative elongation rates and water content of rice root declined. At the same time, POD, SOD and CAT activities decreased in 200 mg/L Fe^2＋ treatment except the POD activity of Xieyou 9308 under the static culture. The restraining rates of POD, SOD and CAT activities were higher in rice root under the shaking culture. The content of Fe in rice root increased heavily and had a significant difference between CK and Fe^＋ stress treatment group. The content of Fe in section of rice root from 0-2 mm to 8-10 mm was increased gradually under the static culture, but had no significant difference in rice root under the shaking culture except the section of 8-10 mm rice root. These results indicate that root border cells play a significant role in resistance to ferrous toxicity of rice.
出处
《中国水稻科学》
CAS
CSCD
北大核心
2009年第5期503-508,共6页
Chinese Journal of Rice Science
基金
浙江省自然科学基金资助项目(305102)
