State Key Laboratory of Crop Stress Biology for Arid Areas/Shaanxi Key Laboratory of Apple, College of Horticulture, Northwest A&F University, Yangling, 712100, Shaanxi, China.
Department of Horticulture, Michigan State University, East Lansing, 48824, USA.
Plant Physiol Biochem. 2020 Mar;148:260-272. doi: 10.1016/j.plaphy.2020.01.022. Epub 2020 Jan 20.
Water shortage is one of the main limiting factors in apple (Malus domestica Borkh.) production. Although dopamine is produced in plants and has been linked with response to abiotic stress, the underlying mechanism remains unknown. In this study, physiological analyses revealed that pretreatment with 100 μM dopamine alleviated drought stress in apple seedlings. Dopamine inhibited the degradation of photosynthetic pigments and increased net photosynthetic rate under drought stress. Dopamine also reduced HO content, possibly through direct scavenging and by mediating the antioxidant enzyme activity. Seedlings pretreated with dopamine had higher sucrose and malic acid contents but lower starch accumulation in their leaves. RNA-Seq analysis identified 1052 differentially expressed genes (DEGs) between non-treated and dopamine-pretreated plants under drought. An in-depth analysis of these DEGs revealed that dopamine regulated the expression of genes related to metabolism of nitrogen, secondary compounds, and amino acids under drought stress. In addition, dopamine may improve apple drought tolerance by activating Ca signaling pathways through increased expression of CNGC and CAM/CML family genes. Moreover, analysis of transcription factor expression suggested that dopamine affected drought tolerance mainly through the regulation of WRKY, ERF, and NAC transcription factors.
缺水是苹果（Malus domestica Borkh.）生产的主要限制因素之一。尽管多巴胺在植物中产生，并且与非生物胁迫反应有关，但潜在机制尚不清楚。在这项研究中，生理分析表明，100μM 多巴胺预处理可缓解苹果幼苗的干旱胁迫。多巴胺抑制干旱胁迫下光合色素的降解，提高净光合速率。多巴胺还降低了 HO 的含量，这可能是通过直接清除和调节抗氧化酶活性来实现的。用多巴胺预处理的幼苗在叶片中有更高的蔗糖和苹果酸含量，但淀粉积累较低。RNA-Seq 分析在非处理和多巴胺预处理植物之间鉴定出 1052 个差异表达基因（DEGs）在干旱下。对这些 DEGs 的深入分析表明，多巴胺通过增加 CNGC 和 CAM/CML 家族基因的表达，调节与氮、次生化合物和氨基酸代谢相关的基因表达，从而调节干旱胁迫下的基因表达。此外，多巴胺可能通过增加 CNGC 和 CAM/CML 家族基因的表达来激活 Ca 信号通路，从而提高苹果的耐旱性。此外，转录因子表达分析表明，多巴胺主要通过调节 WRKY、ERF 和 NAC 转录因子来影响耐旱性。
