Effects of Exogenous ALA on Leaf Photosynthesis, Photosynthate Transport, and Sugar Accumulation in Prunus persica L.

Peaches/nectarines (Prunus persica L.) are widely cultivated worldwide. As with other species, the sugar content is most important trait for fruit quality, especially precocious cultivars. Most fruits need to improve their in order be more profitable under fierce market competition. 5-Aminolevulinic acid (ALA), a naturally occurring δ-amino acid, has been shown leaf photosynthesis and content. However, mechanisms not clear. The objective of this study determine effects exogenous ALA on photosynthesis, assimilate transport, accumulation during development. We used field-cultivated nectarine ‘Zhongyoutao 4’ potted peach ‘Zhongai 33’ as materials, whereas second experiment, we 14C radiolabeling trace fixation leaves, transport branches, distribution different organs. results showed that significantly enhanced photosynthetic gas exchange capacity, were maintained at least one month. radiolabel experiment promoted fruits, reduced allocation rate young leaves. This suggests enlarges “source” volume strengthens “sink” competition; therefore, translocation promoted. It was observed sucrose contributed main saccharide quality maturity, which might converted from glucose or fructose but starch degradation. improved well degradation maturity. RT-qPCR expression genes involved metabolism did correlate even negatively expressions SWEET1/6/7/8/15/16/17 highly correlated content, treatment up-regulated gene suggesting they play an role accumulation. These provide theoretical support application improvement, regulatory mechanism fruits.