Table_2_Physiological and Transcriptional Responses to Saline Irrigation of Young ‘Tempranillo’ Vines Grafted Onto Different Rootstocks.xlsx

The use of more salt stress-tolerant vine rootstocks can be a sustainable strategy for adapting traditional grapevine cultivars to future conditions. However, how the new M1 and M4 rootstocks perform against salinity compared to conventional ones, such as the 1103-Paulsen, had not been previously assessed under real field conditions. Therefore, a field trial was carried out in a young ‘Tempranillo’ (Vitis vinifera L.) vineyard grafted onto all three rootstocks under a semi-arid and hot-summer Mediterranean climate. The vines were irrigated with two kinds of water: a non-saline Control with EC of 0.8 dS m–1 and a Saline treatment with 3.5 dS m–1. Then, various physiological parameters were assessed in the scion, and, additionally, gene expression was studied by high throughput sequencing in leaf and berry tissues. Plant water relations evidenced the osmotic effect of water quality, but not that of the rootstock. Accordingly, leaf-level gas exchange rates were also reduced in all three rootstocks, with M1 inducing significantly lower net photosynthesis rates than 1103-Paulsen. Nevertheless, the expression of groups of genes involved in photosynthesis and amino acid metabolism pathways were not significantly and differentially expressed. The irrigation with saline water significantly increased leaf chloride contents in the scion onto the M-rootstocks, but not onto the 1103P. The limitation for leaf Cl– and Na+ accumulation on the scion was conferred by rootstock. Few processes were differentially regulated in the scion in response to the saline treatment, mainly, in the groups of genes involved in the flavonoids and phenylpropanoids metabolic pathways. However, these transcriptomic effects were not fully reflected in grape phenolic ripeness, with M4 being the only one that did not cause reductions in these compounds in response to salinity, and 1103-Paulsen having the highest overall concentrations. These results suggest that all three rootstocks confer short-term salinity tolerance to the scion. The lower transcriptomic changes and the lower accumulation of potentially phytotoxic ions in the scion grafted onto 1103-Paulsen compared to M-rootstocks point to the former being able to maintain this physiological response in the longer term. Further agronomic trials should be conducted to confirm these effects on vine physiology and transcriptomics in mature vineyards.

采用耐盐性更强的葡萄砧木，可作为将传统葡萄品种适应未来环境条件的一种可持续策略。然而，与传统的1103-Paulsen砧木相比，新的M1和M4砧木在耐盐性方面的表现，尚未在真实田间条件下进行评估。因此，在一个年轻的‘Tempranillo’（Vitis vinifera L.）葡萄园中进行了田间试验，该葡萄园采用所有三种砧木嫁接，位于半干旱和夏季炎热的地中海气候区。葡萄园灌溉了两种类型的水：一种非盐质Control水，电导率为0.8 dS m–1，另一种盐质处理水，电导率为3.5 dS m–1。随后，在接穗上评估了各种生理参数，并且通过高通量测序在叶片和浆果组织中研究了基因表达。植物水分关系证实了水质对渗透效应的影响，但砧木的影响并不显著。因此，在所有三种砧木中，叶片的气体交换速率也有所降低，其中M1较之1103-Paulsen诱导了显著更低的净光合作用速率。尽管如此，参与光合作用和氨基酸代谢途径的基因组的表达并未显著且不同地发生。使用盐水灌溉显著增加了嫁接在M砧木上的接穗叶片中的氯含量，但在1103P上并未增加。接穗上叶Cl–和Na+积累的限制由砧木所赋予。在接穗中，对盐处理的响应中，只有少数过程被差异调节，主要涉及黄酮类和苯丙烷类代谢途径的基因组。然而，这些转录组效应并未完全反映在葡萄酚类成熟度上，M4是唯一一种在盐胁迫下不降低这些化合物含量的砧木，而1103-Paulsen具有最高的总浓度。这些结果表明，所有三种砧木都能赋予接穗短期耐盐性。与M砧木相比，嫁接在1103-Paulsen上的接穗的转录组变化较小，潜在植物毒害离子的积累也较低，这表明前者能够在较长时间内维持这种生理反应。应进一步开展农业试验，以证实这些对成熟葡萄园生理和转录组学的影响。