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Abstract Background Growing evidence demonstrates that the synergistic interaction of far-red light with shorter wavelength lights could evidently improve the photosynthesis efficiency of multiple species. However, whether/how far-red light affects sink organs and consequently modulates the source‒sink relationships are largely unknown. Results Here, equal intensities of white and far-red lights were added to natural light for grape plantlets to investigate the effects of far-red light supplementation on grapevine growth and carbon assimilate allocation, as well as to reveal the underlying mechanisms, through physiological and transcriptomic analysis. The results showed that additional far-red light increased stem length and carbohydrate contents in multiple organs and decreased leaf area, specific leaf weight and dry weight of leaves in comparison with their counterparts grown under white light. Compared to white light, the maximum net photosynthetic rate of the leaves was increased by 31.72% by far-red light supplementation, indicating that far-red light indeed elevated the photosynthesis efficiency of grapes. Transcriptome analysis revealed that leaves were most responsive to far-red light, followed by sink organs, including stems and roots. Genes related to light signaling and carbon metabolites were tightly correlated with variations in the aforementioned physiological traits. In particular, VvLHCB1 is involved in light harvesting and restoring the balance of photosystem I and photosystem II excitation, and VvCOP1 and VvPIF3, which regulate light signal transduction, were upregulated under far-red conditions. In addition, the transcript abundances of the sugar transporter-encoding genes VvSWEET1 and VvSWEET3 and the carbon metabolite-encoding genes VvG6PD, VvSUS7 and VvPGAM varied in line with the change in sugar content. Conclusions This study showed that far-red light synergistically functioning with white light has a beneficial effect on grape photosystem activity and is able to differentially affect the growth of sink organs, providing evidence for the possible addition of far-red light to the wavelength range of photosynthetically active radiation (PAR).

Abstract Clustered regularly interspaced short palindromic repeats (CRISPR) /Cas12a system, also known as CRISPR/Cpf1, has been successfully harnessed for genome engineering in many plants, but not in grapevine yet. Here we developed and demonstrated the efficacy of CRISPR/Cas12a from Lachnospiraceae bacterium ND2006 (LbCas12a) in inducing targeted mutagenesis by targeting the tonoplastic monosaccharide transporter1 (TMT1) and dihydroflavonol-4-reductase 1 (DFR1) genes in 41B cells. Knockout of DFR1 gene altered flavonoid accumulation in dfr1 mutant cells. Heat treatment (34℃) improved the editing efficiencies of CRISPR/LbCas12a system, and the editing efficiencies of TMT1-crRNA1 and TMT1-crRNA2 increased from 35.3% to 44.6% and 29.9% to 37.3% after heat treatment, respectively. Moreover, the sequences of crRNAs were found to be predominant factor affecting editing efficiencies irrespective of the positions within the crRNA array designed for multiplex genome editing. In addition, genome editing with truncated crRNAs (trucrRNAs) showed that trucrRNAs with 20 nt guide sequences were as effective as original crRNAs with 24 nt guides in generating targeted mutagenesis, whereas trucrRNAs with shorter regions of target complementarity ≤ 18 nt in length may not induce detectable mutations in 41B cells. All these results provide evidence for further applications of CRISPR/LbCas12a system in grapevine as a powerful tool for genome engineering. Graphical Abstract

Abstract Grape quality is regulated by complex interactions between environments and cultivars. Growing suitable cultivars in a given region is essential for maintaining viticulture sustainability, particularly in the face of climate change. We created a database composed of three different subsets of data. The first subset was created by digitizing and curating the seminal report of Amerine and Winkler (1944), which provided grape harvest dates (GHDs), the quality of musts and wines, and wine tasting notes for 148 cultivars from 1935–1941 across five contrasting climatic regions of California. To put this dataset into a climate change context, we collected GHDs and must sugar content (°Brix) records from 1991 to 2018 for four representative cultivars in one of the five studied regions (Napa). Finally, we integrated meteorological data of the five regions during 1911–2018 and calculated bioclimatic indices important for grape. The resulting database is unique and valuable for assessing the fitness between cultivars across environments in order to mitigate the effects of climate change. Design Type(s) Cultivars design • Regions design Measurement Type(s) Climate data • Harvest date • Quality • Tasting notes Technology Type(s) Phenology characterization • Quality determination Sample Characteristic(s) Grape harvest dates • °Brix • Tannin • Total acid • pH • Alcohol • Fixed acid • Extract Measurement(s) maximum air temperature • minimum air temperature • total soluble solids (oBrix) • must total acid • must pH • wine alcohol • wine extract • wine tannin • wine total acid • wine volatile acid Technology Type(s) weather station • a oBrix hydrometer • titration with sodium hydroxide to a phenolphthalein end point • a quinhydrone electrode or a Beckman pH meter • hydrometer • a special 0° to 8° Balling hydrometer • the Association of Official Agricultural Chemists method • titration with phenolphthalein as an indicator • titration with pretreated wines by method II of the Association of Official Agricultural Chemists

Climate change is known to simultaneously increase berry sugars but decrease anthocyanins, leading to an imbalance between sugars and anthocyanins in grape berries. To restore the balance of sugars and anthocyanins, carbon limitation by leaf removal and exogenous abscisic acid (ABA) were separately or simultaneously applied to Vitis vinifera cv. Cabernet Sauvignon fruit cuttings to decipher their effects on berry quality with metabolite and whole-genome transcriptome analyses. Carbon limitation decreased the hexose concentration and fully blocked the accumulation of anthocyanins. However, exogenous ABA increased the anthocyanin concentration under both carbon limitation and sufficient conditions. Carbon limitation and exogenous ABA induced the profound remodeling of the whole-genome transcriptome and altered the anthocyanin concentration by regulating the transcription levels of genes involved in the anthocyanin biosynthesis pathways as well as in the genes involved in various types of hormone signaling. Moreover, two pertinent candidate genes were identified based on the co-expression network analysis between the berry metabolite and transcriptome results, including a transcriptional factor, ERF2, and a calcineurin B-like protein-interacting protein kinase gene, CIPK25. In summary, simultaneously modifying the carbon supply by leaf removal and spraying exogenous ABA could re-establish the balance between sugars and anthocyanins to improve the qualities of grape berries via whole-genome transcriptome remodeling.

As a perennial plant with long productive span of 30–50 years, grapevine may experience cross-lifespan climate change, which can modify wine quality and challenge viticultural sustainability. Therefore, it is essential to evaluate the viticultural suitability by considering both current and future climate conditions. To this end, a maximum entropy model was proposed to delimitate potentially suitable areas for viticulture based on multi-source data in a novel wine region, Ningxia, China, considering both current and future climate conditions. Firstly, we combined traditional data of climate, soil, and topography with remote sensing data to screen predictors that best characterize current geographical distribution of vineyards. Then, we used those predictors to assess current suitability (2001–2020) in Ningxia. The results indicated altitude, aridity index during April–September (K0409), precipitation during July–September (P0709), normalized difference vegetation index during July–September (NDVI0709), soil organic carbon (SOC), and precipitation in September (P09) were key predictors to assess potential suitability for viticulture, and their threshold values ranged from 1075 m to 1648 m, 2.93 to 4.83, 103.1 mm to 164.1 mm, 0.1 to 0.89, 0.07 g/kg to 11 g/kg and 28.4 mm to 45.0 mm, respectively. Suitability maps revealed a total suitable area of 12029 km2, among which the highly and moderately suitable areas accounted for 6.1% and 23.1%, respectively. Finally, the alteration in proportion of potential suitable areas due to changing climate was estimated. The potential suitable areas varied from 8742 km2 to 10623 km2 over the next 40 years (2022–2060) and decreased to 8826–9184 km2 under a short-term sustainability (suitable only during current–2040). To further consider long-term and sustainable development of the wine industry (current–2060), total suitable areas dropped by 26.7–29.2% under different climate scenarios compared with current suitable areas (2001–2020). The conclusions provide indispensable guidance for vineyard zoning considering long-term climate change.