Laboratory of Molecular Plant Physiology, Department of Biology, Federal University of Lavras, Lavras, Brazil.
Technological Center of Grape and Wine Research, Agronomical Research Institute of Minas Gerais, Caldas, Brazil.
Sci Rep. 2020 Jun 11;10(1):9514. doi: 10.1038/s41598-020-66500-0.
Bud necrosis (BN) is a common disorder that affects Vitis vinifera L. and reduces its potential yield. To minimize the losses caused by BN, the double pruning management was applied in Brazilian Southeast vineyards. In this management strategy plants are pruned at the winter to promote a vegetative cycle and then, at summer, to promote the reproductive cycle at optimal environmental conditions. To investigate the relationship of BN and the double pruning management RNA-seq libraries were sequenced from healthy and necrotic tissues at four different stages of the year. The comparison of differentially expressed genes in necrotic and non-necrotic tissues showed an enhanced expression of genes related to cell death possibly induced by endophytic microorganisms in the necrotic tissues. The de novo assembly, characterization and quantification of transcripts within the RNA-seq libraries showed that genes from the endophytic fungus Alternaria alternata, responsible for the production of toxic compounds were highly expressed under BN. Here we propose a model in which unfavorable conditions and reduced carbohydrate levels in buds can promote the switch from a biotrophic lifestyle to a necrotrophic lifestyle in the endophytic fungi, which seems to be involved in the development of BN.
葡萄芽坏死（BN）是一种常见的疾病，会影响葡萄属植物的生长并降低其潜在产量。为了最大限度地减少 BN 造成的损失，巴西东南部的葡萄园采用了双修剪管理。在这种管理策略中，植物在冬季进行修剪以促进营养生长周期，然后在夏季，在最佳环境条件下促进生殖生长周期。为了研究 BN 与双修剪管理之间的关系，我们从健康和坏死组织中提取 RNA 并进行了测序，这些组织分别取自一年中的四个不同阶段。对坏死和非坏死组织中差异表达基因的比较表明，坏死组织中细胞死亡相关基因的表达增强，这可能是内生微生物诱导的。通过 de novo 组装、特征分析和 RNA-seq 文库中转录本的定量分析表明，内生真菌交链格孢菌（Alternaria alternata）产生的有毒化合物的基因在 BN 下高度表达。在这里，我们提出了一个模型，即芽内不利条件和碳水化合物水平降低可能会促进内生真菌从生物营养型向坏死营养型的转变，这似乎与 BN 的发生有关。
