The Papaya Transcription Factor CpNAC1 Modulates Carotenoid Biosynthesis through Activating Phytoene Desaturase Genes CpPDS2/4 during Fruit Ripening.
Papaya fruits accumulate carotenoids during fruit ripening. Although many papaya carotenoid biosynthesis pathway genes have been identified, the transcriptional regulators of these genes have not been characterized. In this study, a NAC transcription factor, designated as CpNAC1, was characterized from papaya fruit. CpNAC1 was localized exclusively in nucleus and possessed transcriptional activation activity. Expression of carotenoid biosynthesis genes phytoene desaturases (CpPDSs) and CpNAC1 was increased during fruit ripening and by propylene treatment, which correlates well with the elevated carotenoid content in papaya. The gel mobility shift assays and transient expression analyses demonstrated that CpNAC1 directly binds to the NAC binding site (NACBS) motifs in CpPDS2/4 promoters and activates them. Collectively, these data suggest that CpNAC1 may act as a positive regulator of carotenoid biosynthesis during papaya fruit ripening possibly via transcriptional activation of CpPDSs such as CpPDS2/4.
State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources/Guangdong Key Laboratory for Postharvest Science, College of Horticultural Science, South China Agricultural University , Guangzhou 510642, China.
Chang-Chun
CC
Fu
State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources/Guangdong Key Laboratory for Postharvest Science, College of Horticultural Science, South China Agricultural University , Guangzhou 510642, China.
Yan-Chao
YC
Han
State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources/Guangdong Key Laboratory for Postharvest Science, College of Horticultural Science, South China Agricultural University , Guangzhou 510642, China.
Zhong-Qi
ZQ
Fan
State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources/Guangdong Key Laboratory for Postharvest Science, College of Horticultural Science, South China Agricultural University , Guangzhou 510642, China.
Jian-Ye
JY
Chen
State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources/Guangdong Key Laboratory for Postharvest Science, College of Horticultural Science, South China Agricultural University , Guangzhou 510642, China.
Wei-Xin
WX
Chen
State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources/Guangdong Key Laboratory for Postharvest Science, College of Horticultural Science, South China Agricultural University , Guangzhou 510642, China.
Wang-Jin
WJ
Lu
State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources/Guangdong Key Laboratory for Postharvest Science, College of Horticultural Science, South China Agricultural University , Guangzhou 510642, China.
Jian-Fei
JF
Kuang
D029441:Carica / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D002338:Carotenoids / Q000096:biosynthesis*; D005638:Fruit / Q000201:enzymology / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D010088:Oxidoreductases / Q000235:genetics / Q000378:metabolism*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
D010940:Plant Proteins; D014157:Transcription Factors; D002338:Carotenoids; D010088:Oxidoreductases; C022398:phytoene dehydrogenase
NAC; carotenoids; papaya fruit; phytoene desaturase genes; transcriptional regulation