Global warming will significantly affect grapevine growth and development. To analyze the effects of high temperature on the leaf tissue structure of grapevines in the field, 19 representative cultivars were selected from the grapevine germplasm resources garden in Turpan Research Institute of Agricultural Sciences, XAAS. Twelve tissue structure indexes of grapevine leaves, including the thickness of the upper epidermis (TUE), the thickness of palisade tissue (TPT), leaf vein (LV), the thickness of spongy tissue (TST), the thickness of the lower epidermis (TLE), stoma (St), guard cell (GC), cuticle (Cu), leaf tissue compactness (CTR) and leaf tissue porosity (SR), were measured during the natural high-temperature period in Turpan. The results showed significant differences in the leaf tissue structure of the 19 grapevine cultivars under natural high temperature. Based on the comprehensive comparative analysis of the leaf phenotype in the field, we identified that the leaves of some cultivars, including ‘Zaoxia Wuhe’, ‘Centennial Seedless’ and ‘Kyoho’ showed strong heat tolerance, whereas grapevine cultivars ‘Golden Finger’, ‘Shine Muscat’, ‘Flame Seedless’, ‘Bixiang Wuhe’ and ‘Thompson Seedless’ showed sensitivity to high temperature. We further evaluated the heat tolerance of different grapevine cultivars by principal component analysis and the optimal segmentation clustering of ordered samples. These findings provide a theoretical basis for adopting appropriate cultivation management measures to reduce the effect of high temperatures and offer fundamental knowledge for future breeding strategies for heat-tolerant grapevine varieties.

Temperature is one of the most important environmental factors affecting grape season growth and geographical distribution. With global warming and the increasing occurrence of extreme high-temperature weather, the impact of high temperatures on grape production has intensified. Therefore, identifying the molecular regulatory networks and key genes involved in grape heat tolerance is crucial for improving the resistance of grapes and promoting sustainable development in grape production. In this study, we observed the phenotypes and cellular structures of four grape varieties, namely, Thompson Seedless (TS), Brilliant Seedless (BS), Jumeigui (JMG), and Shine Muscat (SM), in the naturally high-temperature environment of Turpan. Heat tolerance evaluations were conducted. RNA-seq was performed on 36 samples of the four varieties under three temperature conditions (28°C, 35°C, and 42°C). Through differential expression analysis revealed the fewest differentially expressed genes (DEGs) between the heat-tolerant materials BS and JMG, and the DEGs common to 1890 were identified among the four varieties. The number of differentially expressed genes within the materials was similar, with a total of 3767 common DEGs identified among the four varieties. KEGG enrichment analysis revealed that fatty acid metabolism, starch and sucrose metabolism, plant hormone signal transduction, the MAPK signaling pathway, and plant-pathogen interactions were enriched in both between different temperatures of the same material, and between different materials of the same temperature. We also conducted statistical and expression pattern analyses of differentially expressed transcription factors. Based on Weighted correlation network analysis (WGCNA), four specific modules highly correlated with grape heat tolerance were identified by constructing coexpression networks. By calculating the connectivity of genes within the modules and expression analysis, six candidate genes (VIT_04s0044g01430, VIT_17s0000g09190, VIT_01s0011g01350, VIT_01s0011g03330, VIT_04s0008g05610, and VIT_16s0022g00540) related to heat tolerance were discovered. These findings provide a theoretical foundation for further understanding the molecular mechanisms of grape heat tolerance and offer new gene resources for studying heat tolerance in grapes.

High temperatures significantly affect the growth and development of grapevines, cause irreversible damage to plants, and severely impact grape production and quality. Biostimulants can promote the growth of plants and enhance their resistance to adverse stress. However, the effects of biostimulants on grapevines under high temperatures have not been studied in detail. To analyze the effects of various biostimulants on the growth and development of grape seedlings under high temperatures, we measured chlorophyll fluorescence parameters with observed seedling phenotypes under high temperatures in open field conditions in Turpan. We conducted a comprehensive analysis of the effects of different biostimulants on the growth, development, and photosynthesis of grapevine seedlings. Our study aimed to provide scientific evidence to improve cultivation methods for grapevines under high-temperature stress. The results revealed that biostimulants have a positive effect on promoting the growth of grapevine seedlings under high-temperature stress conditions. They also positively affect the accumulation of chlorophyll components in grapevine leaves, inhibiting chlorophyll degradation and maintaining photosynthesis. However, the effects of different biostimulants were inconsistent. A comprehensive analysis revealed the following effectiveness order: T2 > T1 > T3 > Control. These findings suggest that T2 is the most effective in alleviating high-temperature stress and promoting grapevine growth. We recommend the use of T2 to improve the cultivation of grapevine seedlings during high-temperature periods. This has implications for grape production in hot and arid climatic areas.

Laccase, a copper-containing oxidoreductase, has close links with secondary metabolite biosynthesis in plants. Its activity can affect the synthesis and accumulation of secondary metabolites, thereby influencing plant growth, development, and stress resistance. This study aims to identify the grape laccases (VviLAC) gene family members in grape (Vitis vinifera L.) and explore the transcriptional regulatory network in berry development. Here, 115 VviLACs were identified and divided into seven (Type I–VII) classes. These were distributed on 17 chromosomes and out of 47 VviLACs on chromosome 18, 34 (72.34%) were involved in tandem duplication events. VviLAC1, VviLAC2, VviLAC3, and VviLAC62 were highly expressed before fruit color development, while VviLAC4, VviLAC12, VviLAC16, VviLAC18, VviLAC20, VviLAC53, VviLAC60 and VviLAC105 were highly expressed after fruit color transformation. Notably, VviLAC105 showed a significant positive correlation with important metabolites including resveratrol, resveratrol dimer, and peonidin-3-glucoside. Analysis of the transcriptional regulatory network predicted that the 12 different transcription factors target VviLACs genes. Specifically, WRKY and ERF were identified as potential transcriptional regulatory factors for VviLAC105, while Dof and MYB were identified as potential transcriptional regulatory factors for VviLAC51. This study identifies and provides basic information on the grape LAC gene family members and, in combination with transcriptome and metabolome data, predicts the upstream transcriptional regulatory network of VviLACs.

The Munake grape is a local variety of grape that is widely distributed in Xinjiang, China. This study aims to clarify the genetic structure of the Munake grape population, characterize genetic differentiation and gene flow among populations, gather germplasm, and establish the core germplasm collection. In total, 144 samples were collected from eight geographic populations. Twenty-two SSR markers were used to characterize the genetic diversity as well as the genetic structure of Munake grape germplasm and to establish the core germplasm collection. At each site, the average number of effective alleles (Ne) was 5.019. Overall, genetic diversity was high in the various geographic populations of Munake grapes. Polymorphic information content (PIC) ranged from 0.501 to 0.908, with an average of 0.728. Estimates of genetic differentiation and gene flow indicated that the Artux population had significant genetic differences from the other populations. Screening results indicated that a sampling proportion of 95% of the sample was required to achieve 100% allelic coverage, or a sampling proportion of 65% for 95% allelic coverage. This analysis was based on conventional genetic diversity indicators, with a core germplasm diversity index of 95% coverage. Characterization of the genetic diversity of germplasm from 144 Munake grapes not only provides valuable resources for future genetic mapping and functional genome research, but also facilitates the utilization of core germplasm and molecular breeding of Munake grapes.

Leaf senescence is a precisely regulated developmental process that is critical for grapevine growth and yield, which is easily influenced by environmental factors. High temperature is a major factor that accelerates senescence rapidly, adversely affects photosynthetic performance, severely hindering fruit nutrient metabolism and growth. This study investigated chlorophyll fluorescence and physiological traits in grape (Vitis vinifera L.) leaves at different senescence stages under natural high-temperature conditions in Turpan. Measurements included chlorophyll content, MDA levels, antioxidant enzyme activities, and chlorophyll fluorescence parameters. The results showed that (1) young leaves exhibited higher and more sustained chlorophyll content but were prone to wilting, whereas older leaves showed accelerated chlorosis and functional decline; (2) high temperature severely impaired PSII function, inhibiting electron transport and photochemical efficiency, reflected in increased ABS/RC, TR_o/RCC, and DI_o/RC, and decreased F_v/F_m, F_v/F_o, and PI_abs; (3) POD, SOD, CAT and MDA levels initially increased then decreased, correlating with photosynthetic changes and leaf age; and (4) young leaves maintained stronger photosynthetic capability and physiological resilience than older ones. Although partial recovery occurred after temperature reduction, photosynthetic and antioxidant activities did not fully revert. This suggests persistent heat-induced functional decline and accelerated senescence, providing insights for understanding heat-induced leaf senescence and developing strategies for cultivating grapevines.