作者列表：Shuzhen Luo, Chunliu Pan, Songying Liu, Guoting Liao, Ailing Li, Yalun Wang, Aiqin Wang, Dong Xiao, Long-Fei He, Jie Zhan

期刊：PLANT PHYSIOLOGY AND BIOCHEMISTRY

影响因子：5.437

发表时间：2022-11-4

DOI:10.1016/j.plaphy.2022.11.002

Abstract

The toxicity of aluminum （Al） in acidic soil is a prevalent problem ａnd causes reduced crop yields. In the plant response to Al toxicity, programmed cell death （PCD） appears to be an important mechanism. The plant cell wall of crop roots is the predominant site targeted by Al. Here, studies of the capacities of different cell wall constituents （pectin, hemicellulose 1 {HC1} ａnd HC2） to adsorb Al indicated that HC1 has the greater ability to bind Al. The activity of xyloglucan endotransglucosylase （XET） was significantly inhibited by Al in the Al-tolerant peanut cultivar ‘99–1507’ compared to that in ‘ZH 2’ （Al-sensitive）. Results from qPCR analysis suggested that the suppression of XET activity by Al was transcriptionally regulated ａnd that xyloglucan endotransglucosylase/hydrolase 32 （AhXTH32） was the major contributor to these changes. The overexpression of AhXTH32 in Arabidopsis strongly inhibited root growth with a loss of viability in root cells ａnd the occurrence of typical hallmarks of PCD, while largely opposite effects were observed after xth32 suppression. AhXTH32 contributed to the modulation XET ａnd xyloglucan endohydrolase （XEH） activity in vivo. Taken together, our results demonstrate that Al-tolerant peanut cultivar root tips cell walls bind Al predominantly in the HC1 fraction, which results in the inhibition of AhXTH32, with consequences to root growth, Al sensitivity, the occurrence of PCD ａnd the XET/XEH activity ratio.