TY - JOUR

T1 - Calmodulin‐like protein CML24 interacts with CAMTA2 and WRKY46 to regulate ALMT1‐dependent Al resistance in Arabidopsis thaliana

AU - Zhu, Xue

AU - Wang, Peng

AU - Bai, Zhimin

AU - Herde, Marco

AU - Ma, Yanqi

AU - Li, Na

AU - Liu, Shuo

AU - Huang, Chao

AU - Cui, Rongxiu

AU - Hongyu, Ma

AU - Zhang, Meng

AU - Wang, Hui

AU - Wei, Tiandi

AU - Quan, Taiyong

AU - Zhang, Wei

AU - Liu, Chunguang

AU - Zhang, Tao

AU - Yang, Zhong Bao

N1 - Funding Information: We thank Prof. Walter J. Horst (Institute of Plant Nutrition, Leibniz University Hannover) for constructive comments on the manuscript, Prof. Shaojian Zheng (Zhejiang University), Prof. Hiroyuki Koyama (Gifu University), Prof. Michael F. Thomashow (Michigan State University), Prof. Kazuko Yamaguchi‐Shinozaki and Satoshi Kidokoro (Tokyo University) for sharing the published materials. This work was financially supported by the National Natural Science Foundation of China (31670259, 31872655, 32070303 and 31400227), Shandong Provincial Key Research and Development Program (2019GSF107005), the Shandong Provincial Natural Science Foundation Project (ZR2014CQ021), and the Fundamental Research Funds of Shandong University (2018JC059). We would like to thank Haiyan Yu, Xiaoming Zhao, Sen Wang and Yuyu Guo from the State Key laboratory of Microbial Technology of Shandong University for assistance with microscopy imaging, and Chengjia Zhang for assistance with Al analysis with GFS‐AAS.

PY - 2022/2/17

Y1 - 2022/2/17

N2 - ALUMINUM-ACTIVATED MALATE TRANSPORTER1 (ALMT1)-mediated malate exudation from roots is critical for aluminium (Al) resistance in Arabidopsis. Its upstream molecular signalling regulation is not yet well understood. The role of CALMODULIN-LIKE24 (CML24) in Al-inhibited root growth and downstream molecular regulation of ALMT1-meditaed Al resistance was investigated. CML24 confers Al resistance demonstrated by an increased root-growth inhibition of the cml24 loss-of-function mutant under Al stress. This occurs mainly through the regulation of the ALMT1-mediated malate exudation from roots. The mutation and overexpression of CML24 leads to an elevated and reduced Al accumulation in the cell wall of roots, respectively. Al stress induced both transcript and protein abundance of CML24 in root tips, especially in the transition zone. CML24 interacts with CALMODULIN BINDING TRANSCRIPTION ACTIVATOR2 (CAMTA2) and promotes its transcriptional activity in the regulation of ALMT1 expression. This results in an enhanced malate exudation from roots and less root-growth inhibition under Al stress. Both CML24 and CAMTA2 interacted with WRKY46 suppressing the transcriptional repression of ALMT1 by WRKY46. The study provides novel insights into understanding of the upstream molecular signalling of the ALMT1-depdendent Al resistance.

AB - ALUMINUM-ACTIVATED MALATE TRANSPORTER1 (ALMT1)-mediated malate exudation from roots is critical for aluminium (Al) resistance in Arabidopsis. Its upstream molecular signalling regulation is not yet well understood. The role of CALMODULIN-LIKE24 (CML24) in Al-inhibited root growth and downstream molecular regulation of ALMT1-meditaed Al resistance was investigated. CML24 confers Al resistance demonstrated by an increased root-growth inhibition of the cml24 loss-of-function mutant under Al stress. This occurs mainly through the regulation of the ALMT1-mediated malate exudation from roots. The mutation and overexpression of CML24 leads to an elevated and reduced Al accumulation in the cell wall of roots, respectively. Al stress induced both transcript and protein abundance of CML24 in root tips, especially in the transition zone. CML24 interacts with CALMODULIN BINDING TRANSCRIPTION ACTIVATOR2 (CAMTA2) and promotes its transcriptional activity in the regulation of ALMT1 expression. This results in an enhanced malate exudation from roots and less root-growth inhibition under Al stress. Both CML24 and CAMTA2 interacted with WRKY46 suppressing the transcriptional repression of ALMT1 by WRKY46. The study provides novel insights into understanding of the upstream molecular signalling of the ALMT1-depdendent Al resistance.

KW - ALMT1

KW - Arabidopsis roots

KW - CML24

KW - aluminium

KW - malate exudation

UR - http://www.scopus.com/inward/record.url?scp=85118488661&partnerID=8YFLogxK

U2 - 10.1111/nph.17812

DO - 10.1111/nph.17812

M3 - Article

VL - 233

SP - 2471

EP - 2487

JO - New Phytologist

JF - New Phytologist

SN - 0028-646X

IS - 6

ER -