Arabidopsis AtbHLH112 regulates the expression of genes involved in abiotic stress tolerance by binding to their E‐box and GCG‐box motifs. Issue 3 (1st April 2015)

• Record Type: Journal Article
• Authors: Liu, Yujia; Ji, Xiaoyu; Nie, Xianguang; Qu, Min; Zheng, Lei; Tan, Zilong; Zhao, Huimin; Huo, Lin; Liu, Shengnan; Zhang, Bing; Wang, Yucheng
• Is Part Of: New phytologist. Volume 207:Issue 3(2015)
• Page Start: 692
• Page End: 709
• Publication Date: 2015-04-01
• Subjects: Botany -- Periodicals; 580
• DOI: 10.1111/nph.13387
• Languages: English
• ISSNs: 0028-646X

Abstract

<abstract abstract-type="main" id="nph13387-abs-0001"> <title>Summary</title> <p> <list id="nph13387-list-0001" list-type="bullet"> <list-item> <p>Plant basic helix–loop–helix (bHLH) transcription factors play essential roles in abiotic stress tolerance. However, most bHLHs have not been functionally characterized. Here, we characterized the functional role of a bHLH transcription factor from <italic>Arabidopsis</italic>, AtbHLH112, in response to abiotic stress.</p> </list-item> <list-item> <p>AtbHLH112 is a nuclear‐localized protein, and its nuclear localization is induced by salt, drought and abscisic acid (ABA). In addition, AtbHLH112 serves as a transcriptional activator, with the activation domain located at its N‐terminus.</p> </list-item> <list-item> <p>In addition to binding to the E‐box motifs of stress‐responsive genes, AtbHLH112 binds to a novel motif with the sequence 'GG[GT]CC[GT][GA][TA]C' (GCG‐box). Gain‐ and loss‐of‐function analyses showed that the transcript level of <italic>AtbHLH112</italic> is positively correlated with salt and drought tolerance. AtbHLH112 mediates stress tolerance by increasing the expression of <italic>P5CS</italic> genes and reducing the expression of <italic>P5CDH</italic> and <italic>ProDH</italic> genes to increase proline levels. AtbHLH112 also increases the expression of <italic>POD</italic> and <italic>SOD</italic> genes to improve reactive oxygen species (ROS) scavenging ability.</p> </list-item> <list-item> <p>We present a model suggesting that AtbHLH112 is a transcriptional activator that regulates the expression of genes via binding to their GCG‐ or E‐boxes to mediate physiological responses, including proline biosynthesis and ROS scavenging pathways, to enhance stress tolerance.</p> </list-item> </list> </p> </abstract>