Ca2+/Calmodulin Complex Triggers CAMTA Transcriptional Machinery Under Stress in Plants: Signaling Cascade and Molecular Regulation

Zahra Iqbal; Mohammed Shariq Iqbal; Surendra Pratap Singh; Teerapong Buaboocha

doi:10.3389/fpls.2020.598327

Ca²⁺/Calmodulin Complex Triggers CAMTA Transcriptional Machinery Under Stress in Plants: Signaling Cascade and Molecular Regulation

Front Plant Sci. 2020 Dec 3:11:598327. doi: 10.3389/fpls.2020.598327. eCollection 2020.

Authors

Zahra Iqbal¹, Mohammed Shariq Iqbal², Surendra Pratap Singh³, Teerapong Buaboocha^{1

4}

Affiliations

¹ Molecular Crop Research Unit, Department of Biochemistry, Chulalongkorn University, Bangkok, Thailand.
² Amity Institute of Biotechnology, Amity University, Uttar Pradesh, Lucknow Campus, Lucknow, India.
³ Plant Molecular Biology Laboratory, Department of Botany, Dayanand Anglo-Vedic (PG) College, Chhatrapati Shahu Ji Maharaj University, Kanpur, India.
⁴ Omics Sciences and Bioinformatics Center, Faculty of Science, Chulalongkorn University, Bangkok, Thailand.

Abstract

Calcium (Ca²⁺) ion is a critical ubiquitous intracellular second messenger, acting as a lead currency for several distinct signal transduction pathways. Transient perturbations in free cytosolic Ca²⁺ ([Ca²⁺]_cyt) concentrations are indispensable for the translation of signals into adaptive biological responses. The transient increase in [Ca²⁺]_cyt levels is sensed by an array of Ca²⁺ sensor relay proteins such as calmodulin (CaM), eventually leading to conformational changes and activation of CaM. CaM, in a Ca²⁺-dependent manner, regulates several transcription factors (TFs) that are implicated in various molecular, physiological, and biochemical functions in cells. CAMTA (calmodulin-binding transcription activator) is one such member of the Ca²⁺-loaded CaM-dependent family of TFs. The present review focuses on Ca²⁺ as a second messenger, its interaction with CaM, and Ca²⁺/CaM-mediated CAMTA transcriptional regulation in plants. The review recapitulates the molecular and physiological functions of CAMTA in model plants and various crops, confirming its probable involvement in stress signaling pathways and overall plant development. Studying Ca²⁺/CaM-mediated CAMTA TF will help in answering key questions concerning signaling cascades and molecular regulation under stress conditions and plant growth, thus improving our knowledge for crop improvement.

Keywords: CAMTA; calcium; calmodulin; development; stress; transcription factor.

Publication types

Review