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Chloroplast simple sequence repeat (cpSSR) markers previously reported were used to analyze chloroplast diversity of Chinese grapes. Nine cpSSR primer pairs from the chloroplast genomes of citrus and tobacco (Nicotiana tabacum L.) were found useful for analyzing the grapes chloroplast genome (cpDNA). Selected cpSSR primer pairs showed polymorphism among 64 varieties, with polymorphism information content (PIC) values ranging from 0.522 to 0.659, with an average of 0.590. Results depicted that a total number of 43 alleles were detected on nine loci with an average of 4.77 alleles per locus with highest number of six alleles for marker ARCP2 and CCMP10. Gene diversity explained by these cpSSR makers ranged from 4 to 68% with an average of 63.66% per marker. The genetic relationship suggested by UPGMA based dendrogram divided the genotypes into three main clusters and four subgroups, results showed that 2B is the biggest group. Overall Hong Ma Ge and Da LI Mei Gui Xiung 98% similar, while 64-1-19 was the most diverse as compared to rest of genotypes. [ABSTRACT FROM AUTHOR]

GRAS domain genes are a group of important plant-specific transcription factors that have been reported to be involved in plant development. In order to know the roles of GRAS genes in grapevine, a widely cultivated fruit crop, the study on grapevine GRAS ( VvGRAS) was carried out, and from which, 43 were identified from 12× assemble grapevine genomic sequences. Further, the genomic structures, synteny, phylogeny, expression profiles in different tissues of these genes, and their roles in response to stress were investigated. Among the genes, two potential target genes ( VvSCL15 and VvSCL22) for VvmiR171 were experimentally verified by PPM-RACE and RLM-RACE, in that not only the cleavage sites of miR171 on the target mRNA were mapped but also the cleaved fragments and their expressing patterns were detected. Transgenic Arabidopsis plants over expression VvSCL15 showed lower tolerance to drought and salt treatments. [ABSTRACT FROM AUTHOR]

Polyphenols are secondary metabolites widely present in plants which benefit to human health. In the present study we analyzed the changes of polyphenol contents during strawberry fruit development as well as changes of polyphenol oxidase (PPO). The results depicted that the polyphenol content showed a decreasing trend with the fruit development. The pH value impacts the PPO activity, and in strawberry fruit the optimal pH for the PPO activity was 4.5. Meanwhile, PPO activity kept decreasing with the development of the fruit flesh and achenes. The damaged fruit enhanced the PPO activity. We found four PPO genes encoding the PPO in the strawberry that had different expression levels in tissues. The overexpression of the FaPPO1 genes improved the PPO activity in strawberry fruit and delays the fungus infection process. The FaPPO1 gene expression changes had affected the pathogen-related gene expression, such as PAL, SOD, POD, BG, and Chitinase genes. The fruit damage induced the FaPPO1 gene expression, and the abscisic acid and methyl jasmonic were also involved in the regulation of FaPPO1 gene expression. The FaPPO1 and FaPPO2 gene expressions were regulated both by abiotic stresses of low temperature, NaCl, and HO and biotic stresses of powdery mildew and gray mold. Understanding the regulation mechanism of PPO will be helpful and provide meaningful ideas in future for strawberry breeders. [ABSTRACT FROM AUTHOR]

Fruit ripening is a complex process that is regulated by a signal network. Whereas the regulatory mechanism of abscisic acid has been studied extensively in non-climacteric fruit, little is know about other signaling pathways involved in this process. In this study, we performed that plant hormone jasmonic acid plays an important role in grape fruit coloring and softening by increasing the transcription levels of several ripening-related genes, such as the color-related genes PAL1, DFR, CHI, F3H, GST, CHS, and UFGT; softening-related genes PG, PL, PE, Cell, EG1, and XTH1; and aroma-related genes Ecar, QR, and EGS. Lastly, the fruit anthocyanin, phenol, aroma, and cell wall materials were changed. Jasmonic acid positively regulated its biosynthesis pathway genes LOS, AOS, and 12-oxophytodienoate reductase ( OPR) and signal pathway genes COI1 and JMT. RNA interference of grape jasmonic acid pathway gene VvAOS in strawberry fruit appeared fruit un-coloring phenotypes; exogenous jasmonic acid rescued this phenotypes. On the contrary, overexpression of grape jasmonic acid receptor VvCOI1 in the strawberry fruit accelerated the fruit-ripening process and induced some plant defense-related gene expression level. Furthermore, jasmonic acid treatment or strong jasmonic acid signal pathway in strawberry fruit make the fruit resistance against Botrytis cinerea. [ABSTRACT FROM AUTHOR]

With more copper and copper-containing compounds used as bactericides and fungicides in viticulture, copper homeostasis in grapevine ( Vitis) has become one of the serious environmental crises with great risk. To better understand the regulation of Cu homeostasis in grapevine, grapevine seedlings cultured in vitro with different levels of Cu were utilized to investigate the tolerance mechanisms of grapevine responding to copper availability at physiological and molecular levels. The results indicated that Cu contents in roots and leaves arose with increasing levels of Cu application. With copper concentration increasing, malondialdehyde (MDA) content increased in roots and leaves and the activities of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) increased to protect the plant itself from damage. The expression patterns of 19 genes, encoding transporters, chaperones, and P-type ATPases involved in copper homeostasis in root and leaf of grapevine seedling under various levels of Cu were further analyzed. The expression patterns indicated that CTr1, CTr2, and CTr8 transporters were significantly upregulated in response both to Cu excess and deficiency. ZIP2 was downregulated in response to Cu excess and upregulated under Cu-deficient conditions, while ZIP4 had an opposite expression pattern under similar conditions. The expression of chaperones and P-type ATPases in response to Cu availability in grapevine were also briefly studied. [ABSTRACT FROM AUTHOR]

Improper application of copper-based fungicides has made copper stress critical in viticulture, necessitating the need to identify substances that can mitigate it. In this study, leaves of 'Shine Muscat' ('SM') grapevine seedlings were treated with CuSO 4 solution (10 mM/L), CuSO 4 + 5-aminolevulinic acid (ALA) (50 mg/L), and distilled water to explore the mitigation effect of ALA. Physiological assays demonstrated that ALA effectively reduced malondialdehyde accumulation and increased peroxidase and superoxide dismutase activities in grapevine leaves under copper stress. Copper ion absorption, transport pathways, chlorophyll metabolism pathways, photosynthetic system, and antioxidant pathways play key roles in ALA alleviated-copper stress. Moreover, expression changes in genes, such as CHLH , ALAD , RCA, and DHAR, play vital roles in these processes. Furthermore, abscisic acid reduction caused by NCED down-regulation and decreased naringenin, leucopelargonidin, and betaine contents confirmed the alleviating effect of ALA. Taken together, these results reveal how grapevine responds to copper stress and the alleviating effects of ALA, thus providing a novel means of alleviating copper stress in viticulture. [Display omitted] • Exogenous application of 5-aminolevulinic acid alleviates copper stress in grapevine. • ALA restores suppressed photosynthesis under copper stress. • Antioxidant systems and phytohormone metabolism were induced to alleviate copper stress. [ABSTRACT FROM AUTHOR]

The development of precision agriculture calls for the emergence of new approaches to more accurately depict plant phenology. Gene expression data can predict and indicate plant growth state and phenological events accurately at the molecular level, and thus could be developed as a novel means of describing crop phenophase. Here, we analyzed the expression profiles of nine genes involved in grapevine flower and berry development, and screened the most informative genes for use in depicting grapevine phenology. Of the genes tested, VvAP1, VvAP3, VvFLC were found to be best suited to depicting grapevine phenology. The feasibility and efficiency of using the genetically depicted grapevine phenology was further tested in fertilization trials. The results showed that fertilization could be used to decrease flower and berry drop ratio and increase berry weight and size to a greater extent when taking into account variations in the activity of specific genes. Thus, phenologies predicted by a knowledge of gene activity can definitely be formed, and can be regarded as 'genetic phenology'. A first grapevine genetic phenology profile was completed, and used to pre-depict grapevine phenophases to accurately guide the timing of grapevine farming activities and in the pre-diagnosis of the influence of some stresses on grapevines. Genetic phenology could be developed into a simple, low-cost and highly effective technology for accurate prediction of traditional crop phenology at the molecular level that is well suited to precision agriculture. [ABSTRACT FROM AUTHOR]