ANTISENSE ACID INVERTASE (MAI1) GENE ALTERS SOLUBLE SUGAR COMPOSITION AND SIZE IN TRANSGENIC MUSKMELON FRUIT
Invertase (-fructosidase, EC 126.96.36.199) hydrolyzes sucrose to hexose sugars and thus plays a fundamental role in the energy requirements for plant growth and maintenance. Transgenic plants with altered extracellular acid invertase have highly disturbed growth habits. We cloned an acid invertase cDNA fragment from muskmelon and investigated the role of intracellular soluble acid invertase in muskmelon plant and fruit development. Transgenic muskmelon (Cucumis melo L.) plants expressing a constitutive antisense invertase transgene grew more weakly than wild-type plants. Transgenic fruit expressing a constitutive antisense invertase gene had increased sugar concentrations and had greatly reduced levels of acid invertase in ripe fruit. Sugar-accumulating fruits were approximately 30% smaller than control fruit, and this differential growth correlated with high rates of sugar accumulation during the last stage of development. These data suggest that soluble acid invertase controls sugar composition in muskmelon fruit and that this change in composition contributes to alterations in fruit size.
Xiyan Yu, , Jide Fan, , Qingguo Kong, and Xiufeng Wang, (2007). ANTISENSE ACID INVERTASE (MAI1) GENE ALTERS SOLUBLE SUGAR COMPOSITION AND SIZE IN TRANSGENIC MUSKMELON FRUIT. Acta Hortic. 763, 237-244
β-fructosidase, sucrose, fructose, glucose