biologia plantarum

Biologia plantarum 59:201-210, 2015 | DOI: 10.1007/s10535-015-0504-3

Identification, cloning, and expression analysis of three phytoene synthase genes from Cucurbita pepo

Á. Obrero¹, C. I. González-Verdejo¹, B. Román¹, P. Gómez², J. V. Die³, C. Ampomah-Dwamena^4,*

¹ Centro Alameda del Obispo, IFAPA, Córdoba, Spain

² Centro La Mojonera, IFAPA, La Mojonera, Almería, Spain

³ Instituto de Agricultura Sostenible, CSIC, Córdoba, Spain

⁴ New Zealand Institute for Plant and Food Research Limited, Auckland, New Zealand

An essential step in the carotenoid biosynthesis pathway is the formation of phytoene by phytoene synthase (PSY). In this study, three new genes coding PSYs (CpPSYA, CpPSYB, and CpPSYC) were cloned from Cucurbita pepo and their expression patterns analysed in three cultivars of summer squash which had a different carotenoid content. The gene sequences had a high similarity with those from other plant species, and their predicted proteins were significantly different from each other. A phylogenetic analysis indicates that CpPSYA and CpPSYB shared a high homology and were also homologous with PSYs from others cucurbits, whereas CpPSYC was more closely related to orthologues from strawberry and carrot. An expression analysis revealed that CpPSYA had a higher expression in flowers compared to leaves and showed a differential expression during fruit development. The amount of CpPSYA transcript was higher in fruits with a higher carotenoid content than in those with a lower carotenoid content. However, CpPSYB and CpPSYC showed a relatively high expression in leaves, and their expression in fruits varied among the different cultivars and fruit tissues. These results suggest that the CpPSY genes were under different regulatory mechanisms and they may have different roles in C. pepo.

Keywords: fruit development; phylogenetic tree; summer squash; transcriptional analysis

Subjects: gene expression; phytoene synthase; carotenoid biosynthesis; carotenoids; phylogenetic tree; fruit development; summer squash

Species: Cucurbita pepo

Received: June 23, 2014; Revised: November 17, 2014; Accepted: November 24, 2014; Published: June 1, 2015Show citation