Aluminium-induced reduction of plant growth in alfalfa (Medicago sativa) is mediated by interrupting auxin transport and accumulation in roots

作者：Wang, Shengyin; Ren, Xiaoyan; Huang, Bingru; Wang, Ge; Zhou, Peng^*; An, Yuan^*

来源：Scientific Reports, 2016, 6(1): 30079.

DOI：10.1038/srep30079

• TRANSITION ZONE
• ARABIDOPSIS SEEDLINGS
• CELL-DIFFERENTIATION
• EFFLUX FACILITATOR
• INDUCED INHIBITION
• AL TOLERANCE
• DISTAL PART
• ACID SOILS
• TOXICITY
• MAIZE

The objective of this study was to investigate Al3+-induced IAA transport, distribution, and the relation of these two processes to Al3+-inhibition of root growth in alfalfa. Alfalfa seedlings with or without apical buds were exposed to 0 or 100 mu M AlCl3 and were foliar sprayed with water or 6 mg L-1 IAA. Aluminium stress resulted in disordered arrangement of cells, deformed cell shapes, altered cell structure, and a shorter length of the meristematic zone in root tips. Aluminium stress significantly decreased the IAA concentration in apical buds and root tips. The distribution of IAA fluorescence signals in root tips was disturbed, and the IAA transportation from shoot base to root tip was inhibited. The highest intensity of fluorescence signals was detected in the apical meristematic zone. Exogenous application of IAA markedly alleviated the Al3+-induced inhibition of root growth by increasing IAA accumulation and recovering the damaged cell structure in root tips. In addition, Al3+ stress upregulated expression of AUX1 and PIN2 genes. These results indicate that Al3+-induced reduction of root growth could be associated with the inhibitions of IAA synthesis in apical buds and IAA transportation in roots, as well as the imbalance of IAA distribution in root tips.

• 出版日期2016-7-20
• 单位上海交通大学; rutgers