Gene Details:

• MSU gene ID: LOC_Os03g21060
• RAPdb gene ID: Os03g0327800
• Gene Symbol: OsNAP
• Genome: MSU7 ,  IRGSP-1.0
• Species: Oryza sativa

Functional Descriptions:

• OsNAP-overexpressing transgenic plants displayed an accelerated leaf senescence phenotype at the grain-filling stage, which might be caused by the elevated JA levels and the increased expression of the JA biosynthesis-related genes LOX2 and AOC1, and showed enhanced tolerance ability to MeJA treatment at the seedling stage.
• Analysis of the OsNAP transcript levels in rice showed that this gene was significantly induced by ABA and abiotic stresses, including high salinity, drought and low temperature.
• The NAC family transcription factor OsNAP confers abiotic stress response through the ABA pathway.
• RESULTS: In this study, we reported a member of the NAC transcription factor family named OsNAP whose expression is associated with leaf senescence, and investigated its preliminary function during the process of leaf senescence.
• The results of qRT-PCR showed that the OsNAP transcripts were accumulated gradually in response to leaf senescence and treatment with methyl jasmonic acid (MeJA).
• Nevertheless, the leaf senescence process was delayed in OsNAP RNAi transgenic plants with a dramatic drop in JA levels and with decreased expression levels of the JA biosynthesis-related genes AOS2, AOC1 and OPR7.
• CONCLUSIONS: These results suggest that OsNAP acts as a positive regulator of leaf senescence and this regulation may occur via the JA pathway.
• Rice plants overexpressing OsNAP did not show growth retardation, but showed a significantly reduced rate of water loss, enhanced tolerance to high salinity, drought and low temperature at the vegetative stage, and improved yield under drought stress at the flowering stage.
• Our data suggest that OsNAP functions as a transcriptional activator that plays a role in mediating abiotic stress responses in rice.
• OsNAP is a member of the NAC transcription factor family; it is localized in the nucleus, and shows transcriptional activator activity in yeast.
• Microarray analysis of transgenic plants overexpressing OsNAP revealed that many stress-related genes were up-regulated, including OsPP2C06/OsABI2, OsPP2C09, OsPP2C68 and OsSalT, and some genes coding for stress-related transcription factors (OsDREB1A, OsMYB2, OsAP37 and OsAP59).
• OsNAP connects abscisic acid and leaf senescence by fine-tuning abscisic acid biosynthesis and directly targeting senescence-associated genes in rice.
• Additionally, reduced OsNAP expression leads to delayed leaf senescence and an extended grain-filling period, resulting in a 6.3% and 10.3% increase in the grain yield of two independent representative RNAi lines, respectively.
• Thus, fine-tuning OsNAP expression should be a useful strategy for improving rice yield in the future.

Function-related keywords:

• grain ,  ABA ,  senescence ,  ja ,  yield ,  flower ,  abiotic-stress ,  transcription-factor ,  leaf ,  salinity ,  drought ,  seedling ,  jasmonic ,  temperature ,  growth ,  jasmonic-acid ,  vegetative ,  abscisic-acid ,  leaf-senescence ,  abscisic-acid-biosynthesis ,  grain-filling

Literature:

• The NAC family transcription factor OsNAP confers abiotic stress response through the ABA pathway .  DOI:  10.1093/pcp/pct204 ;  PMID:  24399239
• Identification and functional characterization of a rice NAC gene involved in the regulation of leaf senescence .  DOI:  10.1186/1471-2229-13-132 ;  PMID:  24028154
• OsNAP connects abscisic acid and leaf senescence by fine-tuning abscisic acid biosynthesis and directly targeting senescence-associated genes in rice .  DOI:  10.1073/pnas.1321568111 ;  PMID:  24951508

Related News:

Gene Resources:

• NCBI ID:
• UniProt accessions:

Sequences: