Pectin Methyesterase and Poly Galactrunase Genes Expression in Relation to Softening and Shelf-life of Organic and Inorganic Grape Berry during Storage

Environmental conditions and physiological factors influence the quality and shelf-life of horticulture crops, but also agriculture management strategies could change the quality parameters of horticulture crops. Firmness is an important quality parameter that determines the eating quality of table grapes (Vitis vinifera). The softening of grape berries during storage has been commonly associated with cell walls pectic polysaccharides decomposition and water loss. To investigate the softening of grape berries during storage, we compared the pectin methyesterase (PME) and poly galactrunase (PG) genes expression, water loss content and firmness of organic and inorganic grape berries stored at 1± 1 °C and 90- 95 RH at 0, 30 and 60 days of storage. Total RNA was isolated from frozen grape berry skin tissue. The accumulation of mRNA encoding PME and PG was examined using qRT-PCR. Our results indicate that the expression of PME and PG of grape berry skin was significantly different between organic and inorganic berries at harvest time and during storage. The pattern of PME and PG genes expression in each period of storage time was varied between organic and inorganic berries. However, at the end of storage the highest PME gene expression, water loss content and softening was observed in organic grape berries. PG expression was varied during storage and at the end of storage, the higher PG expression was observed in inorganic berries compared to organic samples. These results suggest that the expression of PME and PG genes in relation to softening modify in response to agricultural managements.

کلیدواژه ها:

qRT-PCR ، Organic ، Quality ، Softening