Key message

We performed a comparative transcriptome combined with morpho-physiological analyses between two differential cold tolerance in two contrasting apricot cultivars. The revealed candidate genes potentially were identified by differential expression analysis.

Apricot (Prunus armeniaca L.) is a major (non-wood product) forest tree species that is adversely affected by spring frost. However, the mechanisms regulating gene expression in response to frost under natural conditions remains relatively uncharacterized. In this study, we analyzed the phenotypic, anatomical, physiological and molecular characteristics of pistils from two apricot cultivars that differ regarding cold tolerance under spring frost. A total of 217,142,216 and 218,148,439 clean reads were obtained for the cold-tolerant (‘Weixuan 1’) and the cold-sensitive (‘Longwangmao’) sample libraries, respectively. Moreover, 57,689 unigenes (≥ 200 bp long) were identified, with an N50 of 2468 bp and a mean length of 1038.08 bp. Furthermore, 1116 up-regulated and 428 down-regulated differentially expressed genes (DEGs) were identified in the two apricot cultivars. Thirteen DEGs related to Ca²⁺ signaling, four DEGs involved in MAPK cascades, and thirty DEGs encoding transcription factors were affected by spring frost. The most significant transcriptome changes induced by spring frost were related to carbohydrate metabolism, amino acid metabolism, lipid metabolism, secondary metabolites, plant hormone signal transduction, and terpenoid metabolism. Notably, bHLH75, GDSL esterase/lipase EXL3, GDSL esterase/lipase LTL1, and peroxidase-66 were more highly expressed in ‘Weixuan 1’ than in ‘Longwangmao’ under 6:00, suggesting these genes may contribute to the cold tolerance of ‘Weixuan 1’. The reliability of our RNA sequencing results was confirmed by quantitative real-time PCR. The data generated in this study may form the basis of future studies on the mechanisms underlying the cold tolerance of apricot under natural field conditions.

中文翻译：

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比较转录组结合形态生理学分析揭示了两个对比杏（Prunus armeniaca L.）品种的潜在耐冷差异性候选基因。

关键信息

我们进行了一个比较转录组，结合形态生理学分析在两个不同的杏品种的两个不同的耐寒性之间。所揭示的候选基因可能通过差异表达分析来鉴定。

杏（杏）L.）是主要的（非木材产品）林木树种，受到春季霜冻的不利影响。然而，在自然条件下调节基因表达以响应霜冻的机制仍然相对未知。在这项研究中，我们分析了来自两个杏品种的雌蕊的表型，解剖，生理和分子特征，它们在春季霜冻下的耐寒性不同。分别获得了耐寒（'Weixuan 1'）和冷敏感（'Longwangmao'）样品库的总共217,142,216和218,148,439次干净读取。此外，鉴定出57,689个单基因（长≥200 bp），N50为2468 bp，平均长度为1038.08 bp。此外，在两个杏品种中鉴定出1116个上调和428个下调的差异表达基因（DEG）。²⁺信号，参与MAPK级联的四个DEG和编码转录因子的三十个DEG受春季霜冻的影响。春季霜冻诱导的最显着的转录组变化与碳水化合物代谢，氨基酸代谢，脂质代谢，次生代谢产物，植物激素信号转导和萜类化合物代谢有关。值得注意的是，bHLH75，在6:00时'微轩1'中的GDSL酯酶/脂肪酶EXL3，GDSL酯酶/脂肪酶LTL1和过氧化物酶-66的表达高于'龙王毛'，这表明这些基因可能有助于'微轩1'的耐寒性。我们的RNA测序结果的可靠性已通过实时定量PCR证实。在这项研究中产生的数据可能构成对未来在自然田间条件下杏的耐寒性机理的未来研究的基础。