Shading Inhibits Sugar Accumulation in Leaf and Fruit of Jujube (Ziziphus jujuba Mill.)

Abstract

Jujube is a characteristic light-demanding fruit tree, but fruit quality is frequently degraded because of the weak light in protected cultivation facilities in south China. In this study, a black shade net was used to set three light intensities artificially: no shading (0%, control, NS), moderate shading (45%, MS), and severe shading (76%, SS) to investigate the effect of low light on sugar metabolism of jujube. Compared with NS, chlorophyll and carotenoid contents in shaded leaves were increased, while specific leaf weight was decreased. A decrease in sucrose content, rather than fructose and glucose, was the main factor affecting sugar content in shaded leaves and fruits. Low expression of ZjSS2 and ZjSS3 inhibited sugar synthesis in shaded leaves, thereby reducing sucrose content by 23.7% in SS leaf than that in NS. Compared with NS, sucrose content in SS fruit was decreased by 58.1%, which was mainly caused by the down-regulated expression of ZjSS2 and ZjSPS1. In conclusion, sugar accumulation in leaf and fruit with shading treatment was suppressed, which was associated with differential transcription levels of related metabolic genes. The study provides new insights into sugar metabolism in leaf and fruit of phototropic plants under low light environments, such as jujube.

The Influences of Soil and Meteorological Factors on the Growth and Fruit Quality of Chinese Jujube (Ziziphus jujuba Mill.)

“…It is clear from the above that there are various factors affecting the growth and development of jujube trees and fruits. This is consistent with previous studies [ 37 , 38 ]. It is of great importance for the development of the jujube industry to comprehensively analyze the key meteorological factors and soil nutrients that affect the productivity and fruit quality, and screen out the improved cultivars that can adapt to specific environmental conditions.…”

Transcriptome Analysis Reveals the Genes Related to Water-Melon Fruit Expansion under Low-Light Stress

“…Low-light stress reduces the photosynthetic performances of the plants, and the transportation of photosynthetic products from leaves to fruits are also affected [ 6 , 9 ], which ultimately leads to the reduction in the sugar content in fruits. Similar research results have been reported on melon [ 16 ], strawberry [ 6 ] and jujube [ 17 ]. Nitrogen metabolism was disturbed by shading, which induced the decrease in dry matter accumulation, ultimately resulting in the failure of watermelon fruits to expand normally [ 18 ].…”

Shading and Planting Material Type Effects on Some Physiological and Biochemical Compounds Synthesis in Desmodium adscendens Plants Leaves in the Domestication Phase, Daloa, Côte d'Ivoire

“…[37] on tomato has shown that the soluble sugar content is higher in plants grown in the shade compared with those grown in full sun. These results are at odds with those of Wang et al [38] on Ziziphus jujuba Mill and [39] on grapevine (Vitis vinifera). According to them, sugar content reduction is obtained in plants grown in the shade compared with those grown in full sun.…”