FeSTAR2 interacted by FeSTAR1 alters its subcellular location and regulates Al tolerance in buckwheat
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Buckwheat (Fagopyrum esculentum) exhibits high Al tolerance, but only a few genes have been functionally characterized. We previously characterized a half-type ABC transporter, Fagopyrum esculentum sensitive to Al rhizotoxicity1 (FeSTAR1), in buckwheat Al tolerance. This study aims to investigate whether and how another half-type ABC transporter (FeSTAR2) plays role in Al tolerance in buckwheat.
The expression of FeSTAR2 and complementation test in Arabidopsis als3 mutant was examined. The interaction between FeSTAR1 and FeSTAR2 and subcellular location were analyzed by bimolecular fluorescence complementation (BiFC) and yeast two-hybrid (Y2H) assays.
Al rapidly and specifically induced FeSTAR2 expression. Having transmembrane domains, FeSTAR2 localizes to membrane. BiFC and Y2H assays showed that FeSTAR2 could interact with FeSTAR1 which contains only nucleotide binding domain. Intriguingly, interaction between FeSTAR1 and FeSTAR2 altered their locations. Both heterologous expression of FeSTAR2 in als3 and exogenous UDP-glucose rescued its Al hypersensitivity of als3 mutant, suggesting that involvement of FeSTAR2 in Al tolerance requires UDP-glucose. Furthermore, Al-induced inhibition of xyloglucan endotransglucosylase (XET) activity in both atstar1 and als3 mutants could be restored by UDP-glucose.
Our results indicate that FeSTAR2 interacts with FeSTAR1 to form an ABC transporter to regulate Al tolerance by vesicular transport of UDP-glucose which affects hemicellulose metabolism by regulating XET activity.
KeywordsAluminum toxicity Cell wall Protein interaction UDP-glucose Xyloglucan
This work was supported financially by the Natural Science Foundation of China (31572193), 111 project (grant no. B14027), and The Chang Jiang Scholars Program (JLY). We are grateful to Prof. Dong Liu for providing us the Arabidopsis mutant als3 seeds.
- Che J, Yamaji N, Yokosho K, Shen RF, Ma JF (2018) Two genes encoding a bacterial-type ATP-binding cassette transporter are implicated in aluminum tolerance in buckwheat. Plant Cell Physiol 59:2502–2511Google Scholar
- Ma JF, Zheng SJ, Matsumoto H, Hiradate S (1997) Detoxifying aluminium with buckwheat. Nature 390(6660):569–570Google Scholar
- Yang XY, Yang JL, Zhou Y, Piñeros MA, Kochian LV, Li GX, Zheng SJ (2011a) A de novo synthesis citrate transporter, Vigna umbellata multidrug and toxic compound extrusion, implicates in Alactivated citrate efflux in rice bean (Vigna umbellata) root apex. Plant Cell Environ 34:2138–2148CrossRefGoogle Scholar
- Yokosho K, Yamaji N, Ma JF (2014) Global transcriptome analysis of Al-induced genes in an Al-accumulating species, common buckwheat (Fagopyrum esculentum Moench). Plant Cell Physiol 55: 2077–2091Google Scholar
- Zhong X, Wang ZQ, Xiao R, Cao L, Wang Y, Xie Y, Zhou X (2017) Mimic phosphorylation of a βC1 protein encoded by TYLCCNB impairs its functions as a viral suppressor of RNA silencing and a symptom determinant. J Virol 91:e00300–e00317Google Scholar