The overexpression of OsNAC9 alters the root architecture of rice plants enhancing drought resistance and grain yield under field conditions

• Published in: Plant biotechnology journal 2012-09, Vol.10 (7), p.792-805
• Main Authors: Redillas, Mark C.F.R., Jeong, Jin S., Kim, Youn S., Jung, Harin, Bang, Seung W., Choi, Yang D., Ha, Sun-Hwa, Reuzeau, Christophe, Kim, Ju-Kon
• Format: Article
• Language: English
• Subjects: Abiotic stress; Abscisic acid; Adaptation, Physiological; Agricultural production; Agriculture; Biological and medical sciences; Biosynthesis; Biotechnology; Calcium ions; Calcium signalling; Cell death; Corn; Crop production; Crop yield; Crops; Dioxygenase; DNA microarrays; Drought; Drought resistance; Droughts; Fundamental and applied biological sciences. Psychology; Gene expression; Gene Expression Regulation, Plant; Genes; Grain; grain yield; Kinases; Lignin; Methyltransferase; Morphogenesis; NAC; Oryza - genetics; Oryza - growth & development; Oryza - physiology; Phenotypes; Plant Proteins - genetics; Plant Proteins - metabolism; Plant Roots - anatomy & histology; Plant Roots - growth & development; Plants (botany); Plants, Genetically Modified; Real-Time Polymerase Chain Reaction; Reductases; Rice; root architecture; root-specific expression; Roots; Salt; Seeds; Seeds - growth & development; Signal transduction; Stress, Physiological; Transcription factors; Trends; Up-Regulation - genetics
• ISSN: 1467-7644; 1467-7652
• DOI: 10.1111/j.1467-7652.2012.00697.x

Summary Drought conditions limit agricultural production by preventing crops from reaching their genetically predetermined maximum yields. Here, we present the results of field evaluations of rice overexpressing OsNAC9, a member of the rice NAC domain family. Root‐specific (RCc3) and constitutive (GOS2) promoters were used to overexpress OsNAC9 and produced the transgenic RCc3:OsNAC9 and GOS2:OsNAC9 plants. Field evaluations over two cultivating seasons showed that grain yields of the RCc3:OsNAC9 and the GOS2:OsNAC9 plants were increased by 13%–18% and 13%–32% under normal conditions, respectively. Under drought conditions, RCc3:OsNAC9 plants showed an increased grain yield of 28%–72%, whilst the GOS2:OsNAC9 plants remained unchanged. Both transgenic lines exhibited altered root architecture involving an enlarged stele and aerenchyma. The aerenchyma of RCc3:OsNAC9 roots was enlarged to a greater extent than those of GOS2:OsNAC9 and non‐transgenic (NT) roots, suggesting the importance of this phenotype for enhanced drought resistance. Microarray experiments identified 40 up‐regulated genes by more than threefold (P