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Background Nudix hydrolases are widely distributed across all classes of organisms and provide the potential capacity to hydrolyze a wide range of organic pyrophosphates. Although Nudix hydrolases are involved in plants detoxification processes in response to abiotic and biotic stresses, the biological functions of Nudix hydrolases remain largely unclear in grapevine. Results A total of 25 putative grapevine Nudix hydrolases ( VvNUDXs ) were identified by bioinformatics analysis and classified into eight subfamilies based to their preferred substrates. Both tandem and segmental duplications were responsible for the evolution and expansion of NUDX gene family in grapevine. To investigate into their regulatory roles of VvNUDX genes during growth and development as well as in response to abiotic and biotic stress in grapevine, the expression patterns were revealed in publicly available microarray data. The spatial and temporal expression patterns of VvNUDX genes indicated that these genes might play important roles in multiple developmental processes. Transcriptome and qRT-PCR analysis exhibited that ten VvNUDX genes were specifically expressed in grapevine berries, suggesting the potential roles in grapevine berry development. Expression and phylogenetic analysis demonstrated that VvNUDX1 and VvNUDX3 might be involved in terpenoid biosynthesis in grapevine. Futhermore, most VvNUDX genes toward the ADP-ribose/NADH were different patterns in response to various abiotic and biotic stresses, such as salinity and drought, as well as different types of biotic treatments, such as Erysiphe necator , Bois Noir phytoplasma and leaf-roll-associated virus-3 (GLRaV-3). Conclusions These results showed that VvNUDX were associated with plant detoxification processes in response to abiotic and biotic stresses, and regulate disease immunity and resistance pathways. The present informations may provide good opportunities to explore the physiological functions of VvNUDX genes in berry development and stress response networks in grapevine.

Background Grapevine (Vitis vinifera L.), which has important nutritional values and health benefits, is one of the most economically important fruit crops cultivated worldwide. Several studies showed a large number of microRNAs (VvmiRNAs) involved in the modulation of grape growth and development, and many VvmiRNA families have multiple members. However, the way by which various members from the same miRNA family work is unclear, particularly in grapes. Results In this study, an important conserved VvmiR172 family (VvmiR172s) and their targets were set as a good example for elucidating the interaction degree, mechanism, and spatio-temporal traits of diverse members from the same miRNA family. miR-RACE and Stem-loop RT-PCR were used to identify the spatio-temporal expressions of various members of VvmiR172s; together with RLM-RACE, PPM-RACE, Western blot, transgenic technologies, their interaction degree, and regulation mechanism were further validated. The expression of VvmiR172c was significantly higher than that of VvmiR172a, b, and d and showed a positive correlation with the abundance of VvAP2 cleavage products. These findings indicated that VvmiR172c might be one of the main action factors of the VvmiR172 family in flower development. The ability of VvmiR172c to cleave target genes differed due to divergence in complementary degree with VvAP2 and expression levels of various members. In VvmiR172 transgenic lines, we observed that 35S::VvmiR172c resulted in the earliest and abundant flowering, indicating the strong function of VvmiR172c. In contrast, the non-significant phenotypic changes were detected in the VvAP2 transgenic lines. The qRT-PCR and Western bolt results demonstrated that VvmiR172c plays a major role in targeting VvAP2. Conclusions VvmiR172 up-regulated the expression of NtFT and decreased the expression of NtFLC. The up/down regulation of VvmiR172c was the most pronounced. The functions of four VvmiR172 members in grape differed, and miR172c had the strongest regulation on AP2.

Background The plant-specific TCP transcription factors play different functions in multiple processes of plant growth and development. TCP family genes have been identified in several plant species, but no comprehensive analysis of the TCP family in grapevine has been undertaken to date, especially their roles in fruit development. Results A total of 18 non-redundant grapevine TCP (VvTCP) genes distributing on 11 chromosomes were identified. Phylogenetic and structural analysis showed that VvTCP genes were divided into two main classes - class I and class II. The Class II genes were further classified into two subclasses, the CIN subclass and the CYC/TB1 subclass. Segmental duplication was a predominant duplication event which caused the expansion of VvTCP genes. The cis-acting elements analysis and tissue-specific expression patterns of VvTCP genes demonstrated that these VvTCP genes might play important roles in plant growth and development. Expression patterns of VvTCP genes during fruit development and ripening were analyzed by RNA-Seq and qRT-PCR. Among them, 11 VvTCP genes were down-regulated during different fruit developmental stages, while only one VvTCP genes were up-regulated, suggesting that most VvTCP genes were probably related to early development in grapevine fruit. Futhermore, the expression of most VvTCP genes can be inhibited by drought and waterlogging stresses. Conclusions Our study establishes the first genome-wide analysis of the grapevine TCP gene family and provides valuable information for understanding the classification and functions of the TCP genes in grapevine.

b-Carotene content in apple fruits of different cultivars was determined by HPLC to provide some basic information for evaluating fruit quality and for controlling b-carotene of apples with orchard practices and biotechnology. Results showed that b-carotene content in apples was different with various cultivars and strains, orchard practices (bagging or not) and different parts (peel or flesh). b-Carotene content in Fuji Yanfu 3 was higher than Royal Gala and Tuscan. As to the same cultivar, Fuji, b-carotene content in Fuji Beni Shogun, an earlier maturation strain, was higher than Fuji Yanfu 3, a striped red color strain, and higher than Fuji Yanfu 6, a blush red color strain. b-Carotene content of apple peel was usually higher than that of the flesh. b-Carotene content of the peel and flesh in Fuji Yanfu 3 apples was reduced by 30.43% and 4.38% respectively by paper bagging. It suggested that it is possible to produce higher b-carotene content apples with selected cultivars or strains and proper practices.