Isolation and Characterization of DkPK Genes Associated with Natural Deastringency in C-PCNA Persimmon.
Isolation and Characterization of DkPK Genes Associated with Natural Deastringency in C-PCNA Persimmon.
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C-PCNA 柿子中与天然脱涩相关的 DkPK 基因的分离和表征
DOI：
10.3389/fpls.2016.00156
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发表时间：
2016
影响因子：
5.6
通讯作者：
Luo Z
中科院分区：
文献类型：
--
作者：
Guan C;Chen W;Mo R;Du X;Zhang Q;Luo Z
中国常授粉甜柿（Diospyros kaki Thunb.）尽管其去涩的分子机制仍有待阐明，但它被认为是PCNA品种选育的重要种质资源。在此之前，我们发现丙酮酸激酶基因转录本的丰度增加迅速脱涩在C-PCNA柿子果实。在这里，我们报告的全长编码序列的6个新的DkPK基因从C-PCNA柿子果实分离的基础上的互补DNA（cDNA）文库和转录组数据。这6个DkPK基因的表达模式和可溶性原花青素（PA）含量的相关性进行了分析，在不同类型的柿果实发育的各个阶段，与DkPK 1显示在最后阶段的表达模式，在C-PCNA柿，与可溶性PA的减少呈正相关。系统发育分析表明DkPK 1属于胞质1亚群，亚细胞定位分析证实DkPK 1定位于胞质。值得注意的是，组织表达谱揭示了普遍存在的DkPK 1在不同的柿子器官中的表达，在种子中的表达最高。此外，在柿子叶片中瞬时过表达DkPK 1导致可溶性PAs的含量显著降低，但催化丙酮酸转化为乙醛的丙酮酸脱羧酶基因（DkPDC 1，-3，-4，-5）的转录水平显著增加。因此，我们提出基于乙酰丙酮的凝结作用降低了可溶性PA的含量。综上所述，我们的研究结果表明，DkPK 1可能参与了自然消除涩味在最后的发展阶段，在C-PCNA柿。这是第一次报告，以确定几个新的全长DkPK基因，以及他们的潜在作用，在自然失去收敛性的C-PCNA柿。
Chinese pollination-constant non-astringent (C-PCNA) persimmon (Diospyros kaki Thunb.) is considered to be an important germplasm resource for the breeding of PCNA cultivars, though its molecular mechanisms of astringency removal remain to be elucidated. Previously, we showed that the abundance of pyruvate kinase gene transcripts increased rapidly during astringency removal in C-PCNA persimmon fruit. Here, we report the full-length coding sequences of six novel DkPK genes from C-PCNA persimmon fruit isolated based on a complementary DNA (cDNA) library and transcriptome data. The expression patterns of these six DkPK genes and correlations with the soluble proanthocyanidin (PA) content were analyzed during various fruit development stages in different types of persimmon, with DkPK1 showing an expression pattern during the last stage in C-PCNA persimmon that was positively correlated with a decrease in soluble PAs. Phylogenetic analysis revealed that DkPK1 belongs to cytosolic-1 subgroup, and subcellular localization analysis confirmed that DkPK1 is located in the cytosol. Notably, tissue expression profiling revealed ubiquitous DkPK1 expression in different persimmon organs, with the highest expression in seeds. Furthermore, transient over-expression of DkPK1 in persimmon leaves resulted in a significant decrease in the content of soluble PAs but a significant increase in the transcript levels of pyruvate decarboxylase genes (DkPDC1, -3, -4, -5), which catalyze the conversion of pyruvate to acetaldehyde. Thus, we propose that an acetaldehyde-based coagulation effect reduces the content of soluble PAs. Taken together, our results suggest that DkPK1 might be involved in the natural removal of astringency at the last developmental stage in C-PCNA persimmon. This is the first report to identify several novel full-length DkPK genes as well as their potential roles in the natural loss of astringency in C-PCNA persimmon.