荞麦根缘细胞的发育及脱落后对铝毒的响应  

Development of buckwheat root border cells and their impact on Al^(3+) toxicity after being detached

作　　者：蔡妙珍[1] 刘鹏[1] 徐根娣[1] 刘海华[1] 龚春风[1] 

机构地区：[1]浙江师范大学化学与生命科学学院,浙江金华321004

出　　处：《植物营养与肥料学报》2007年第5期925-928,共4页Journal of Plant Nutrition and Fertilizers

基　　金：国家自然科学基金(30540056);浙江省自然科学基金(Y304185;Y303461)资助

摘　　要：采用悬空气培法,研究了荞麦根缘细胞发育过程的形态、活性变化和脱落后对铝(Al3+)毒的响应。结果显示,荞麦根缘细胞绝大多数呈细杆状,少数呈弯曲的长条型。根长25 mm时,根缘细胞中活细胞的比率最大(约94%);果胶甲基酯酶(PME)在根生长至5 mm时,活性最大,此后随着根的伸长,PME活性迅速下降,根长大于25mm时PME活性稳定在最大值的40%。脱离根尖的根缘细胞经50μmol/L Al3+处理,随着处理时间延长,存活率大幅度下降,处理后48 h时,存活率只有5%。铝毒加速离体根缘细胞的死亡。Root border cells, formerly termed ＂sloughed root cap cells＂, are defined as cells separated from each other （the apex） and loosely associated with the root so that they disperse into suspension upon immersion of the root tip into water. In the past, border cells have largely been overlooked as a structural and functional component of root systems, but the recently discovered cellular responses of border cells to nematodes, aluminum and fungi suggested novel mechanisms by which border cells might function to protect the root tip from biotic and abiotic stress. To our knowledge, the possible role of root border cells in Al-tolerance mechanisms has been largely ignored. This study was designed to test the production and development of border cells in buckwheat, and the defense response of border cells in vitro on Al^3＋ toxicity. The results indicated that most root border cells have a slender claval shape, and few of them have a bend claval shape. Border cells can be observed in roots of 1 mm long, and the viability of border cells reached maximum （about 94% ） when the root length was 25mm. PME activity increased with emergence of the radicle （lmm） and remained the highest when the root was 5mm in length, at which time PME levels decreased and remained low through 35mm. The increase in exposure time to 50 μmol/L Al^3＋ significantly decreased the survival percentage of border cells in vitro, and dropped to 5 % after 48 h treatment.

关 键 词：荞麦 根缘细胞 发育 Al^3+毒 

分 类 号：S517[农业科学—作物学]