PDF(Pubmed)
Abstract：
Clematis is the queen of the vines, being an ornamental plant with high economic value. Waterlogging stress reduces the ornamental value of the plant and limits its application. Melatonin plays an important role in plant resistance to abiotic stresses. In this study, the physiological responses and gene expression levels of two wild species, namely, Clematis tientaiensis and Clematis lanuginosa, and two horticultural varieties, namely, \'Sen-No-Kaze\' and \'Viva Polonia,\' under waterlogging stress were analyzed to determine the effect of melatonin on waterlogging tolerance. The results showed that the waterlogging tolerances of C. lanuginosa and \'Sen-No-Kaze\' were relatively poor, but were significantly improved by concentrations of 100 μmol·L-1 and 50 μmol·L-1 melatonin. C. tientaiensis and \'Viva Polonia\' had relatively strong tolerance to waterlogging, and this was significantly improved by 200 μmol·L-1 melatonin. Under waterlogging stress, the relative conductivity and H2O2 content of Clematis increased significantly; the photosynthetic parameters and chlorophyll contents were significantly decreased; photosynthesis was inhibited; the contents of soluble protein and soluble sugars were decreased. Effective improvement of waterlogging tolerance after exogenous melatonin spraying, the relative conductivity was decreased by 4.05%-27.44%; the H2O2 content was decreased by 3.84%-23.28%; the chlorophyll content was increased by 35.59%-103.36%; the photosynthetic efficiency was increased by 25.42%-45.86%; the antioxidant enzyme activities of APX, POD, SOD, and CAT were increased by 28.03%-158.61%; the contents of proline, soluble protein, and soluble sugars were enhanced, and cell homeostasis was improved. Transcription sequencing was performed on wild Clematis with differences in waterlogging tolerance, and nine transcription factors were selected that were highly correlated with melatonin and that had the potential to improve waterlogging tolerance, among which LBD4, and MYB4 were significantly positively correlated with the antioxidant enzyme system, and bHLH36, DOF36, and WRKY4 were significantly negatively correlated. Photosynthetic capacity was positively correlated with DOF36 and WRKY4 while being significantly negatively correlated with MYB4, MOF1, DOF47, REV1 and ABR1. Melatonin could enhance the flooding tolerance of Clematis by improving photosynthetic efficiency and antioxidant enzyme activity. This study provides an important basis and reference for the application of melatonin in waterlogging-resistant breeding of Clematis.
摘要：
铁线莲是葡萄树的女王,是一种具有很高经济价值的观赏植物。淹水胁迫降低了植物的观赏价值，限制了其应用。褪黑素在植物对非生物胁迫的抗性中起重要作用。在这项研究中,两个野生物种的生理反应和基因表达水平，即,铁线莲和铁线莲，和两个园艺品种，即,\'Sen-No-Kaze\'和\'VivaPolonia,对淹水胁迫下的\'进行了分析，以确定褪黑素对耐涝能力的影响。结果表明，铜绿梭菌和“Sen-No-Kaze”的耐涝能力相对较差，但浓度为100μmol·L-1和50μmol·L-1的褪黑激素显着改善。天底草和“紫罗兰”对内涝有相对较强的耐受性，200μmol·L-1褪黑素显著提高。在淹水胁迫下，铁线莲的相对电导率和H2O2含量显著增加；光合参数和叶绿素含量显著降低；光合作用受到抑制；可溶性蛋白和可溶性糖含量降低。外源褪黑素喷施后有效提高耐涝能力,相对电导率降低4.05％-27.44％；H2O2含量降低3.84％-23.28％；叶绿素含量提高35.59％-103.36％；光合效率提高25.42％-45.86％；APX的抗氧化酶活性，POD,SOD,和CAT的含量增加了28.03%-158.61%；脯氨酸的含量，可溶性蛋白质，可溶性糖得到增强，细胞稳态得到改善。对耐涝性差异的野生铁线莲进行转录测序，和9个转录因子是高度相关的褪黑激素，并有可能提高耐涝能力，其中LBD4和MYB4与抗氧化酶系统呈显著正相关,与bHLH36、DOF36、WRKY4呈显著负相关。光合能力与DOF36和WRKY4呈正相关，与MYB4、MOF1、DOF47、REV1和ABR1呈显著负相关。褪黑素可以通过提高光合效率和抗氧化酶活性来增强铁线莲的抗洪能力。本研究为褪黑素在铁线莲抗涝育种中的应用提供了重要依据和参考。
