Xiao Renhao, Han Qin, Liu Yu, Zhang Xuehai, Hao Qingnan, Chai Qingqing, Hao Yongfang, Deng Junbo, Li Xia, Ji Hongtao
National Key Laboratory of Crop Genetic Improvement, Hubei Hongshan Laboratory, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China.
Oil Crops Research Institute, Chinese Academy of Agricultural Sciences, Wuhan, China.
Front Microbiol. 2022 Jul 7;13:903467. doi: 10.3389/fmicb.2022.903467. eCollection 2022.
Foliar application of nitrogen to enhance crop productivity has been widely used. Melatonin is an effective regulator in promoting plant growth. However, the effects of melatonin and the combination of melatonin and nitrogen on soybeans yields production remain largely unknown. In this study, a field experiment was conducted to evaluate the effects and mechanisms of spraying leaves with melatonin and urea on soybeans. Foliar application of urea significantly increased soybean yields and melatonin did not affect the yields, while combination of melatonin and urea significantly reduced the yields compared to the application of urea alone. A leaf transcriptional profile was then carried out to reveal the underlying mechanism and found that foliar spraying of urea specifically induced the expression of genes related to amino acid transport and nitrogen metabolism. However, foliar application of melatonin significantly changed the transcriptional pattern established by urea application and increased the expression of genes related to abiotic stress signaling pathways. The effects of melatonin and urea treatment on soil microbiome were also investigated. Neither melatonin nor urea application altered the soil microbial alpha diversity, but melatonin application changed rhizosphere microbial community structure, whereas the combination of melatonin and urea did not. Melatonin or urea application altered the abundance of certain taxa. The number of taxa changed by melatonin treatment was higher than urea treatment. Collectively, our results provide new and valuable insights into the effects of foliar application of melatonin to urea and further show that melatonin exerts strong antagonistic effects on urea-induced soybean yields, gene expression and certain soil microorganisms.
叶面喷施氮肥以提高作物产量已被广泛应用。褪黑素是促进植物生长的有效调节剂。然而，褪黑素以及褪黑素与氮的组合对大豆产量的影响仍 largely 未知。在本研究中，进行了一项田间试验，以评估叶面喷施褪黑素和尿素对大豆的影响及机制。叶面喷施尿素显著提高了大豆产量，而褪黑素对产量没有影响，与单独喷施尿素相比，褪黑素与尿素的组合显著降低了产量。随后进行了叶片转录谱分析以揭示潜在机制，发现叶面喷施尿素特异性诱导了与氨基酸转运和氮代谢相关基因的表达。然而，叶面喷施褪黑素显著改变了由尿素施用建立的转录模式，并增加了与非生物胁迫信号通路相关基因的表达。还研究了褪黑素和尿素处理对土壤微生物群落的影响。单独喷施褪黑素或尿素均未改变土壤微生物的α多样性，但喷施褪黑素改变了根际微生物群落结构，而褪黑素与尿素的组合则没有。喷施褪黑素或尿素改变了某些分类群的丰度。褪黑素处理改变的分类群数量高于尿素处理。总体而言，我们的结果为叶面喷施褪黑素对尿素的影响提供了新的有价值的见解，并进一步表明褪黑素对尿素诱导的大豆产量、基因表达和某些土壤微生物具有强烈的拮抗作用。
