Cárcamo de la Concepción María, Sargent Daniel James, Šurbanovski Nada, Colgan Richard John, Moretto Marco
Natural Resources Institute, University of Greenwich, Chatham, Kent, United Kingdom.
NIAB EMR, East Malling, Kent, United Kingdom.
PLoS One. 2021 Aug 2;16(8):e0255139. doi: 10.1371/journal.pone.0255139. eCollection 2021.
Fruit firmness and in particular the individual components of texture and moisture loss, are considered the key quality traits when describing blueberry fruit quality, and whilst these traits are genetically regulated, the mechanisms governing their control are not clearly understood. In this investigation, RNAseq was performed on fruits of two blueberry cultivars with very different storage properties, 'Bluecrop' and 'Legacy', at harvest, three weeks storage in a non-modified environment at 4 °C and after three weeks storage at 4 °C followed by three days at 21 °C, with the aim of understanding the transcriptional changes that occur during storage in cultivars with very different post-harvest fruit quality. De novo assemblies of the transcriptomes of the two cultivars were performed separately and a total of 39,335 and 41,896 unigenes for 'Bluecrop' and 'Legacy' respectively were resolved. Differential gene expression analyses were grouped into four cluster profiles based on changes in transcript abundance between harvest and 24 days post-harvest. A total of 290 unigenes were up-regulated in 'Legacy' only, 685 were up-regulated in 'Bluecrop', 252 were up-regulated in both cultivars and 948 were down-regulated in both cultivars between harvest and 24 days post-harvest. Unigenes showing significant differential expression between harvest and following post-harvest cold-storage were grouped into classes of biological processes including stress responses, cell wall metabolism, wax metabolism, calcium metabolism, cellular components, and biological processes. In total 21 differentially expressed unigenes with a putative role in regulating the response to post-harvest cold-storage in the two cultivars were identified from the de novo transcriptome assemblies performed. The results presented provide a stable foundation from which to perform further analyses with which to functionally validate the candidate genes identified, and to begin to understand the genetic mechanisms controlling changes in firmness in blueberry fruits post-harvest.
果实硬度，尤其是质地和水分流失的各个组成部分，在描述蓝莓果实品质时被视为关键品质特征。虽然这些特征受基因调控，但其控制机制尚不清楚。在本研究中，对两个贮藏特性差异很大的蓝莓品种“蓝丰”（Bluecrop）和“遗产”（Legacy）的果实进行了RNA测序，分别在收获时、在4℃非改良环境中贮藏三周后以及在4℃贮藏三周后再在21℃放置三天时进行，目的是了解在采后果实品质差异很大的品种贮藏期间发生的转录变化。分别对两个品种的转录组进行了从头组装，“蓝丰”和“遗产”分别解析出39335个和41896个单基因。基于收获时和采后24天之间转录本丰度的变化，差异基因表达分析被分为四个聚类图谱。在收获时和采后24天之间，共有290个单基因仅在“遗产”中上调，685个在“蓝丰”中上调，252个在两个品种中均上调，948个在两个品种中均下调。在收获时和采后冷藏后显示出显著差异表达的单基因被归类为包括应激反应、细胞壁代谢、蜡代谢、钙代谢、细胞成分和生物学过程等生物学过程类别。从进行的从头转录组组装中总共鉴定出21个在调控两个品种对采后冷藏反应中具有假定作用的差异表达单基因。所呈现的结果提供了一个稳定的基础，在此基础上可以进行进一步分析，以功能验证所鉴定的候选基因，并开始了解控制蓝莓果实采后硬度变化的遗传机制。
