Root tolerance and biochemical response of Chinese lettuce ( Lactuca sativa L.) genotypes to cadmium stress

PeerJ

article

Mohammed Mujitaba Dawuda¹  Weibiao Liao²  Linli Hu²  Jihua Yu²  Jianming Xie²  Alejandro Calderón-Urrea³  Xin Jin⁴  Yue Wu² 

[1] Department of Horticulture, Faculty of Agriculture, University for Development Studies;College of Horticulture, Gansu Agricultural University;Department of Biology, California State University;College of Agriculture and Forest Science, Linyi University, Linyi, Shandong Province

关键词: Cadmium stress;    Antioxidant enzymes;    Endogenous hormones;    Lettuce genotypes;    Root morphology;   

DOI  :  10.7717/peerj.7530

学科分类：社会科学、人文和艺术（综合）

来源: Inra

【 摘 要 】

This study was conducted to determine the root tolerance and biochemical responses of four Chinese Lactuca sativa L. genotypes (Lüsu, Lümeng, Yidali and Anyan) to cadmium (Cd2+) stress. Twenty-eight days old seedlings were exposed to Hoagland’s nutrient solution supplied with or without 100 µM CdCl2 and monitored for seven days in a climate controlled room. The 100 µM CdCl2 significantly (P < 0.001) decreased all the root morphological indexes of the four genotypes. However, Yidali, which possessed the smallest root system, exhibited greater root tolerance to Cd2+ by having the highest tolerance indexes for root volume (46%), surface area (61%), projected area (74%) and numbers of root forks (63%) and root tips (58%). Moreover, Cd2+ stress also caused increases in H2O2 contents in the roots but the increase was least in Yidali which showed greater root tolerance to Cd2+stress. The effect of Cd2+ stress on the contents of hormones in the roots depended on the genotypes. Under Cd2+ stress, abscisic acid correlated positively with indole-3-acetic acid (r = 0.669*), gibberellic acid (r = 0.630*) and cytokinin (r = 0.785**). The antioxidant enzyme activities and proline responses of the four genotypes to Cd2+ stress were similar. The SOD activity was decreased whiles the CAT and POD activities, as well as the contents of proline increased in all the genotypes under the stress condition. These results suggest that lettuce genotypes with smaller root systems could be more tolerant to Cd2+ stress compared to those with larger root systems.

【 授权许可】

CC BY