Auxin treatment of grape (Vitis vinifera L.) berries delays ripening by inducing changes in gene expression and cell wall metabolism and could combat some deleterious climate change effects. Auxins are inhibitors of grape berry ripening and their application may be useful to delay harvest to counter effects of climate change. However, little is known about how this delay occurs. The expression of 1892 genes was significantly changed compared to the control during a 48 h time-course where the auxin 1-naphthaleneacetic acid (NAA) was applied to pre-veraison grape berries. Principal component analysis showed that the control and auxin-treated samples were most different at 3 h post-treatment when approximately three times more genes were induced than repressed by NAA. There was considerable cross-talk between hormone pathways, particularly between those of auxin and ethylene. Decreased expression of genes encoding putative cell wall catabolic enzymes (including those involved with pectin) and increased expression of putative cellulose synthases indicated that auxins may preserve cell wall structure. This was confirmed by immunochemical labelling of berry sections using antibodies that detect homogalacturonan (LM19) and methyl-esterified homogalacturonan (LM20) and by labelling with the CMB3a cellulose-binding module. Comparison of the auxin-induced changes in gene expression with the pattern of these genes during berry ripening showed that the effect on transcription is a mix of changes that may specifically alter the progress of berry development in a targeted manner and others that could be considered as non-specific changes. Several lines of evidence suggest that cell wall changes and associated berry softening are the first steps in ripening and that delaying cell expansion can delay ripening providing a possible mechanism for the observed auxin effects.

中文翻译：

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葡萄藤 (Vitis vinifera L.) 浆果的生长素处理通过抑制细胞扩张来延缓成熟开始。

葡萄 (Vitis vinifera L.) 浆果的生长素处理通过诱导基因表达和细胞壁代谢的变化来延缓成熟，并且可以对抗一些有害的气候变化影响。生长素是葡萄浆果成熟的抑制剂，它们的应用可能有助于延迟收获以应对气候变化的影响。然而，人们对这种延迟是如何发生的知之甚少。在将生长素 1-萘乙酸 (NAA) 应用于转色前葡萄浆果的 48 小时时间过程中，与对照相比，1892 个基因的表达发生了显着变化。主成分分析表明，对照和生长素处理的样品在处理后 3 小时差异最大，此时诱导的基因大约是 NAA 抑制的三倍。激素通路之间存在相当大的交叉对话，特别是在生长素和乙烯之间。编码假定细胞壁分解代谢酶（包括与果胶有关的酶）的基因表达减少和假定纤维素合酶表达增加表明生长素可以保留细胞壁结构。这通过使用检测高半乳糖醛酸 (LM19) 和甲基酯化高半乳糖醛酸 (LM20) 的抗体对浆果切片进行免疫化学标记以及使用 CMB3a 纤维素结合模块进行标记得到证实。将生长素诱导的基因表达变化与浆果成熟过程中这些基因的模式进行比较表明，对转录的影响是多种变化的混合，这些变化可能以有针对性的方式特异性改变浆果发育的进程，而其他可能被认为是非特定的变化。