Project description:The quality of the pepper fruit is significantly influenced by the properties of its surface such as color, glossiness and texture. The fruit surface is composed of a peel containing several layers including the cuticle, epidermis and the hypodermis. The peel acts as a protective barrier against biotic and abiotic stresses and is the most critical tissue affecting water loss during post harvest storage. The peel is composed of an outer epidermis with thick waxy (lipid) cuticle and few cell layers of thick-walled hypodermal cells. Despite its agronomic importance and due to the fact that the majority of studies in fruits have been conducted using flesh and peel tissues as a whole, the biochemical and genetic bases of variation in peel properties are largely unknown. In this proposal we aim to determine peel-specific gene expression in pepper by micro array hybridizations of peel and flesh RNA extracted at different developmental stages of the fruit. The cultivar Celica (Capsicum annuum) that has a large blocky fruit will be used for studying gene expression in the peel and flesh. Plants were grown in the greenhouse during the spring of 2006. Fruits were harvested at three developmental stages: young- 10 days after anthesis, mature green- 30 days after anthesis and ripe red- 45 days after anthesis. These stages were chosen because each represents a distinct phase in fruit development. At each stage, a biological replicate consists of bulked tissue from 3 fruits from each of 3 plants (a total of 9 fruits). We have a total of 4 biological replicates. For each fruit, the peel was separated from the flesh by manual dissection using thin forceps and scalpel blade. Peel and flesh samples were immediately frozen in liquid nitrogen and stored at -800C until RNA extraction. Total RNA was extracted using the GenElute Mammalian Total RNA Miniprep kit (Sigma). Keywords: Reference design
Project description:The quality of the pepper fruit is significantly influenced by the properties of its surface such as color, glossiness and texture. The fruit surface is composed of a peel containing several layers including the cuticle, epidermis and the hypodermis. The peel acts as a protective barrier against biotic and abiotic stresses and is the most critical tissue affecting water loss during post harvest storage. The peel is composed of an outer epidermis with thick waxy (lipid) cuticle and few cell layers of thick-walled hypodermal cells. Despite its agronomic importance and due to the fact that the majority of studies in fruits have been conducted using flesh and peel tissues as a whole, the biochemical and genetic bases of variation in peel properties are largely unknown. In this proposal we aim to determine peel-specific gene expression in pepper by micro array hybridizations of peel and flesh RNA extracted at different developmental stages of the fruit. The cultivar Celica (Capsicum annuum) that has a large blocky fruit will be used for studying gene expression in the peel and flesh. Plants were grown in the greenhouse during the spring of 2006. Fruits were harvested at three developmental stages: young- 10 days after anthesis, mature green- 30 days after anthesis and ripe red- 45 days after anthesis. These stages were chosen because each represents a distinct phase in fruit development. At each stage, a biological replicate consists of bulked tissue from 3 fruits from each of 3 plants (a total of 9 fruits). We have a total of 4 biological replicates. For each fruit, the peel was separated from the flesh by manual dissection using thin forceps and scalpel blade. Peel and flesh samples were immediately frozen in liquid nitrogen and stored at -800C until RNA extraction. Total RNA was extracted using the GenElute Mammalian Total RNA Miniprep kit (Sigma). Keywords: Reference design 12 hybs total
Project description:For identifying genes for sex determination in papaya, digital gene expression analysis by Ht-SuperSAGE (Matsumura et al., 2010) was carried out in flowers from male, female and hermaphrodite plants of papaya. Total more than 9,273,744 26bp-tags were obtained by sequence analysis using SOLiD3 and mapped on papaya primitive sex chromosome sequences.
Project description:For identifying genes for sex determination in papaya, digital gene expression analysis by Ht-SuperSAGE (Matsumura et al., 2010) was carried out in flowers from male, female and hermaphrodite plants of papaya. Total more than 9,273,744 26bp-tags were obtained by sequence analysis using SOLiD3 and mapped on papaya primitive sex chromosome sequences. 6 samples examined: male young flowerbud, male mature flower bud, female young flower bud, female mature flower bud, hermaphrodite young flower bud, hermaphrodite mature flower bud
Project description:Peel color is a key factor that affects the fruit’s aesthetic and economic values. In Red Sugar pineapple, the peels’ red color reduces during maturation. Limited knowledge is available on the regulation of pineapple peel discoloration, which makes it important to study the molecular mechanisms associated with this important trait. Here, we report that a decrease in anthocyanin biosynthesis is predominantly associated with the pineapple peel color change during maturation. Particularly the exclusive accumulation of cyanidin in 60 days after flowering (DAF) as compared to 120 DAF gives the fruit peel its distinct reddish color. Our findings suggest that the changes in the expression of key structural genes (early and late biosynthetic genes) of the anthocyanin (cyanidin) biosynthesis pathway are responsible for peel discoloration. Based on a gene co-expression analysis and a transient expression, we identified two transcription factors i.e., AcHOX21 and AcMYB12, and showed that their downregulation leads to the reduced anthocyanin accumulation with fruit maturation.
Project description:Papaya (Carica papaya L.) is a typical climacteric fruit, undergoing massive physico-chemical changes during ripening. Although papaya is widely cultivated and consumed, few studies have characterized the variations in metabolism during its ripening process at the proteasome level. Using an integrated approach involving Tandem Mass Tag labeling and liquid chromatography–mass spectrometry analysis, proteomes of papaya fruit at different ripening stages were investigated. A total of 3220 proteins were identified, of which 2818 were quantified. The differential accumulated proteins (DAPs) exhibited various biological functions and diverse subcellular localizations. Among the DEPs, most of the pathogen defense-related proteins were down-regulated, suggesting that disease resistance decreased during the ripening process. The Kyoto Encyclopedia of Genes and Genomes enrichment analysis revealed that various metabolic pathways were significantly altered, particularly in flavonoid and fatty acid metabolisms. The up-regulation of several flavonoid biosynthesis-related proteins may provide more raw materials for pigment biosynthesis, accelerating the color variation of papaya fruit. Thus, variations in the fatty acid metabolism-related enzymes were investigated. For example, a lipoxygenase, which catalyzes the conversion of ACC to ethylene, was significantly induced, suggesting a cross-talk between the lipoxygenase-mediated fatty acid metabolism and the hormone-controlled fruit ripening in papaya. Furthermore, the contents of several important fatty acids were determined, and increased unsaturated fatty acids may be associated with papaya fruit volatile formation. Our data may give an intrinsic explanation of the variations in metabolism during the ripening process of papaya fruit and serve as a comprehensive resource for investigating the regulation mechanism involved.