OsNAC5 overexpression enlarges root diameter in rice plants leading to enhanced drought tolerance and increased grain yield in the field.
Plant Biotechnol J
; 11(1): 101-14, 2013 Jan.
Article
em En
| MEDLINE
| ID: mdl-23094910
ABSTRACT
Drought conditions are among the most serious challenges to crop production worldwide. Here, we report the results of field evaluations of transgenic rice plants overexpressing OsNAC5, under the control of either the root-specific (RCc3) or constitutive (GOS2) promoters. Field evaluations over three growing seasons revealed that the grain yield of the RCc3OsNAC5 and GOS2OsNAC5 plants were increased by 9%-23% and 9%-26% under normal conditions, respectively. Under drought conditions, however, RCc3OsNAC5 plants showed a significantly higher grain yield of 22%-63%, whilst the GOS2OsNAC5 plants showed a reduced or similar yield to the nontransgenic (NT) controls. Both the RCc3OsNAC5 and GOS2OsNAC5 plants were found to have larger roots due to an enlarged stele and aerenchyma at flowering stage. Cell numbers per cortex layer and stele of developing roots were higher in both transgenic plants than NT controls, contributing to the increase in root diameter. The root diameter was enlarged to a greater extent in the RCc3OsNAC5, suggesting the importance of this phenotype for enhanced drought tolerance. Microarray experiments identified 25 up-regulated genes by more than three-fold (P < 0.01) in the roots of both transgenic lines. Also identified were 19 and 18 up-regulated genes that are specific to the RCc3OsNAC5 and GOS2OsNAC5 roots, respectively. Of the genes specifically up-regulated in the RCc3OsNAC5 roots, GLP, PDX, MERI5 and O-methyltransferase were implicated in root growth and development. Our present findings demonstrate that the root-specific overexpression of OsNAC5 enlarges roots significantly and thereby enhances drought tolerance and grain yield under field conditions.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Oryza
/
Sementes
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Fatores de Transcrição
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Raízes de Plantas
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Secas
Tipo de estudo:
Prognostic_studies
Idioma:
En
Ano de publicação:
2013
Tipo de documento:
Article