铝对黄瓜和黑籽南瓜RBCs生理特性的影响

Effects of aluminum on physiological characteristics of root border cells of cucumber and figleaf gourd

【目的】探究黄瓜和黑籽南瓜幼苗根系边缘细胞(Root border cells,RBCs)对铝毒的应答差异,进一步阐明黑籽南瓜对铝的抗性机制,为黑籽南瓜作为黄瓜的砧木提供依据。【方法】以‘津研四号’黄瓜和云南黑籽南瓜种子为试材,采用悬空培养法,研究了0(对照,CK),50,100和200μmol/L Al 3+对2种瓜类根畸形率、根长、根鲜质量及RBCs的黏胶层厚度、数目、活率和凋亡率的影响。【结果】与CK相比,随着Al 3+浓度的增大,黄瓜根的畸形率也随之增大,而黑籽南瓜根畸形率无显著变化;2种瓜类的根长、根鲜质量整体均呈下降趋势,但黄瓜根长、根鲜质量下降幅度较黑籽南瓜明显。随着Al 3+浓度的增加,2种瓜类RBCs的数目和活率均明显降低,且黄瓜降低幅度较黑籽南瓜明显;而RBCs凋亡率却随着Al 3+浓度的增加而增大,该现象在黄瓜中较为明显。与CK相比,Al 3+处理明显增加了2种瓜类RBCs的黏胶层厚度,相同Al 3+浓度下黑籽南瓜RBCs的黏胶层厚度均大于黄瓜。【结论】RBCs能提高植物根系抵御Al 3+毒害的能力;黑籽南瓜RBCs因具有数目多、凋亡率低和较厚的黏胶层等特性,故其抵御Al 3+毒害的能力优于黄瓜。

【Objective】This study explored the different responses of root border cells（RBCs）of cucumber and figleaf gourd seedlings to aluminum toxicity.【Method】Changes in root malformation rate,root length,root flesh quality per plant,thickness of mucilage layer of RBCs,number of RBCs,viability of RBCs and apoptosis rate of RBCs in cucumber and figleaf gourd were investigated using floating culture technique with stress of 0（CK）,50,100 and 200μmol/L Al^3＋.【Result】Malformation rate of root and apoptosis rate of RBCs in cucumber seedlings increased with Al^3＋concentration while that in figleaf gourd changed insignificantly.Root length,root flesh quality per plant,number of RBCs and viability of RBCs of both cucumber and figleaf gourd were inhibited by Al^3＋and the inhibition in cucumber was more significant.With the increase of Al^3＋concentration,thicker RBCs mucilage layer was observed in both species and the thickness of figleaf gourd was larger than that of cucumber.【Conclusion】RBCs could enhance the resistance against Al^3＋toxicity.Figleaf gourd seedlings were better because of more number,lower apoptosis rate of RBCs and thicker mucilage layer of RBCs.