Characterization of a wheat (Triticum aestivum L.) expansin gene, TaEXPB23, involved in the abiotic stress response and phytohormone regulation

• Published in: Plant physiology and biochemistry Vol. 54; pp. 49 - 58
• Main Authors: Han, Yang yang, Li, Ai xiu, Li, Feng, Zhao, Mei rong, Wang, Wei
• Format: Journal Article
• Language: English
• Published: Paris Elsevier Masson SAS 01-05-2012; Elsevier
• Subjects: Adaptation, Physiological - genetics; Biological and medical sciences; Expansin gene; Fundamental and applied biological sciences. Psychology; Genes, Plant; High temperature stress; Hot Temperature; Nicotiana - genetics; Osmosis; Phytohormone; Plant Growth Regulators - metabolism; Plant physiology and development; Plant Proteins - genetics; Plants, Genetically Modified; Salt stress; Salt Tolerance - genetics; Sodium Chloride - adverse effects; Stress, Physiological - genetics; Transgenic tobacco; Triticum - genetics; Triticum - growth & development; Triticum - metabolism; Triticum aestivum; Up-Regulation; Water - metabolism; ABA; OP; Salt stress; MS; WRA; IAA; MeJA; HT; ET; NAA; Transgenic tobacco; GAs; Expansin gene; Phytohormone; High temperature stress; WT; Thermal stress; Monocotyledones; Nicotiana; Abiotic stress; Expansin; High temperature; Cereal crop; Salinity; Characterization; Response; Gene; Plant physiology; Gramineae; Dicotyledones; Angiospermae; Spermatophyta; Transgenic plant; Solanaceae; Triticum aestivum
• ISSN: 0981-9428; 1873-2690
• DOI: 10.1016/j.plaphy.2012.02.007

Expansins are proteins that are generally accepted to be key regulators of cell wall extension and plant growth. We examined the expression pattern of TaEXPB23, a wheat (Triticum aestivum L.) expansin gene, under exogenous phytohormone and abiotic stress treatments. In addition, we evaluated its function in the tolerance to salt stress and high temperature (HT) by overexpressing it in transgenic tobacco plants. In subcellular localization assays, TaEXPB23 localized to the cell wall. Expression analysis demonstrated that the transcription pattern of TaEXPB23 corresponded to wheat coleoptile growth. Real-time RT-PCR analysis revealed that TaEXPB23 transcript expression was upregulated by exogenous methyl jasmonate (MeJA) and salt stress, but downregulated by exogenous gibberellins (GA3), ethylene (ET), indole-3-acetic acid (IAA) and α-naphthlcetic acid (NAA). Overexpression of TaEXPB23 in tobacco (tabacum) conferred tolerance to salt stress by enhancing water retention ability (WRA) and decreasing osmotic potential (OP). However, transgenic plants overexpressing TaEXPB23 did not show any improvement in the tolerance to HT stress. These results suggested that TaEXPB23 is regulated by phytohormones and is involved in the regulation of salt stress tolerance.
► TaEXPB23 encodes a cell wall protein. ► In wheat, TaEXPB23 is regulated by multi-phytohormones and abiotic stress. ► Overexpression of TaEXPB23 in tobacco increase tolerance to salt stress. ► The transgenic plants are sensitive to high temperature.