Overexpression of ARGOS Genes Modifies Plant Sensitivity to Ethylene, Leading to Improved Drought Tolerance in Both Arabidopsis and Maize

• Published in: Plant physiology (Bethesda) 2015-09, Vol.169 (1), p.266-282
• Main Authors: Shi, Jinrui, Habben, Jeffrey E., Archibald, Rayeann L., Drummond, Bruce J., Chamberlin, Mark A., Williams, Robert W., Lafitte, H. Renee, Weers, Ben P.
• Format: Article
• Language: English
• Subjects: Adaptation, Physiological - drug effects; Adaptation, Physiological - genetics; Arabidopsis - drug effects; Arabidopsis - genetics; Arabidopsis - physiology; Arabidopsis Proteins - genetics; Arabidopsis Proteins - metabolism; Corn; Down-Regulation - drug effects; Down-Regulation - genetics; Drought; Droughts; Endoplasmic Reticulum - drug effects; Endoplasmic Reticulum - metabolism; Ethylenes - biosynthesis; Ethylenes - pharmacology; FOCUS ON ETHYLENE; Gene Expression Regulation, Plant - drug effects; Genes, Plant; Golgi Apparatus - drug effects; Golgi Apparatus - metabolism; Hybridity; Hypocotyls; Intracellular Membranes - drug effects; Intracellular Membranes - metabolism; Mutation - genetics; Plant Proteins - genetics; Plant Proteins - metabolism; Plant roots; Plants; Plants, Genetically Modified; Receptors; s - Focus Issue; Seedlings; Seeds - drug effects; Seeds - growth & development; Signal Transduction - drug effects; Signal Transduction - genetics; Transgenes; Transgenic plants; Zea mays - drug effects; Zea mays - genetics; Zea mays - physiology
• ISSN: 0032-0889; 1532-2548
• DOI: 10.1104/pp.15.00780

Lack of sufficient water is a major limiting factor to crop production worldwide, and the development of drought-tolerant germplasm is needed to improve crop productivity. The phytohormone ethylene modulates plant growth and development as well as plant response to abiotic stress. Recent research has shown that modifying ethylene biosynthesis and signaling can enhance plant drought tolerance. Here, we report novel negative regulators of ethylene signal transduction in Arabidopsis (Arabidopsis thaliana) and maize (Zea mays). These regulators are encoded by the ARGOS gene family. In Arabidopsis, overexpression of maizeARGOS1(ZmARGOS1),ZmARGOS8, ArabidopsisARGOShomologORGAN SIZE RELATED1(AtOSR1), andAtOSR2reduced plant sensitivity to ethylene, leading to enhanced drought tolerance. RNA profiling and genetic analysis suggested that theZmARGOS1transgene acts between an ethylene receptor and CONSTITUTIVE TRIPLE RESPONSE1 in the ethylene signaling pathway, affecting ethylene perception or the early stages of ethylene signaling. Overexpressed ZmARGOS1 is localized to the endoplasmic reticulum and Golgi membrane, where the ethylene receptors and the ethylene signaling protein ETHYLENE-INSENSITIVE2 and REVERSION-TO-ETHYLENE SENSITIVITY1 reside. In transgenic maize plants, overexpression of ARGOS genes also reduces ethylene sensitivity. Moreover, field testing showed that UBIQUITIN1:ZmARGOS8maize events had a greater grain yield than nontransgenic controls under both drought stress and well-watered conditions.