Effects of low pH and aluminum stresses on common beans (Phaseolus vulgaris) differing in low-phosphorus and photoperiod responses

查看全文 作　　者：Hai [1]NIAN;Cunyi [1]YANG;He [1]HUANG;Hideaki [2]MATSUMOTO 机构地区：[1]College of Agriculture,South China Agricultural University,Guangzhou 510642,China;[2]Research Institute for Bioresources Okayama University,Kurashiki 710-0046,Japan 出　　处：《Frontiers in Biology》索引2009年第4卷第4期,共7页 摘　　要：Using common beans differing greatly in the response to photoperiod and low-phosphorus(P)stress,we investigated their responses to acidity and aluminum(Al)toxicity and the relationship between Al tolerance and organic acid exudation under Al or low P stress.A genotype Ginshi was found to be sensitive to low pH treatment.When exposed to pH 4.5,serious curvature in the root tips of cv.Ginshi was observed;however,it was completely corrected by the application of 5 or 10μmol/L AlCl 3;increasing calcium(Ca)could ameliorate Al toxicity,but it could not correct root curvature at pH 4.5.Common beans showed significant differences in both root growth and Al tolerance,and the varieties from the Andes were more tolerant to Al toxicity than those from the Mesoamerican origin.In the presence of 50μmol/L AlCl 3,all the common bean genotypes exuded citrate,and a significant difference in the amounts of citrate was observed among genotypes.The genotypes originated in the Mesoamerica tended to release more citrate than other origins in the presence of Al.The P-inefficient genotype DOR364 exuded more citrate than the P-efficient genotype G19833 in the presence of 50μmol/L AlCl 3,whereas no organic acids were detected in root exudates under low-P stress.A reduction of citrate exudation in the DOR364,but a slight increase of citrate exudation in the G19833,was observed under Al stress after they were exposed to 6-d P starvation.These results suggest that different low-P or Al tolerance in common beans might not be associated with organic acid exudation. 关 键 词：common bean LOW-PH ALUMINUM organic acid exudation phosphorus deficiency