College of Horticulture, Northwest A&F University, Yangling, Shaanxi 712100, People's Republic of China.
Key Laboratory for Plant Diversity and Biogeography of East Asia, Chinese Academy of Sciences, Kunming Institute of Botany, Kunming 650201, People's Republic of China.
J Agric Food Chem. 2020 Oct 21;68(42):11684-11693. doi: 10.1021/acs.jafc.0c03894. Epub 2020 Oct 8.
Continuous cropping obstacles seriously affect the sustainable production of tomatoes ( L.). Researchers have found that intercropping with garlic ( L.) could alleviate tomato continuous cropping obstacles. Diallyl disulfide (DADS) is the main allelochemical in garlic. However, the mechanism of DADS in alleviating tomato continuous cropping obstacles is still unknown. In this research, aqueous extracts of tomato continuous cropping soil were used to simulate the continuous cropping condition of tomato. Our results showed that DADS increased root activity and chlorophyll content and improved the activity of antioxidant enzymes (superoxide dismutase (SOD), peroxidase (POD), and phenylalanine ammonia-lyase (PAL)) and the metabolism of nonenzymatic antioxidants (glutathione (GSH) and oxidized glutathione (GSSG)) in tomato plants. DADS treatment reduced the content of fatty acid esters in tomato root exudates (e.g., palmitate methyl ester, palmitoleic acid methyl ester, oleic acid methyl ester) and increased the level of substances such as dibutyl phthalate and 2,2'-methylenebis(6--butyl-4-methylphenol). The higher concentrations of palmitate methyl ester inhibited tomato hypocotyl growth, while oleic acid methyl ester inhibited tomato root growth. Moreover, the application of DADS significantly inhibited the secretion of these esters in the root exudates. Therefore, it suggests that DADS may increase tomato resistance and promote tomato plant growth by increasing root activity and photosynthetic capacity and development to reduce autotoxicity of tomato.
连作障碍严重影响番茄（L.）的可持续生产。研究人员发现，与大蒜（L.）间作对可缓解番茄连作障碍。二烯丙基二硫醚（DADS）是大蒜中的主要化感物质。然而，DADS 缓解番茄连作障碍的机制尚不清楚。在这项研究中，使用番茄连作土壤的水提物来模拟番茄的连作条件。我们的结果表明，DADS 增加了番茄根系活力和叶绿素含量，提高了抗氧化酶（超氧化物歧化酶（SOD）、过氧化物酶（POD）和苯丙氨酸解氨酶（PAL））和非酶抗氧化剂（谷胱甘肽（GSH）和氧化型谷胱甘肽（GSSG））的代谢。DADS 处理降低了番茄根分泌物中脂肪酸酯的含量（如棕榈酸甲酯、棕榈油酸甲酯、油酸甲酯），增加了邻苯二甲酸二丁酯和 2,2'-亚甲基双（6--丁基-4-甲基苯酚）等物质的水平。较高浓度的棕榈酸甲酯抑制番茄下胚轴生长，而油酸甲酯抑制番茄根生长。此外，DADS 的应用显著抑制了这些酯类在根分泌物中的分泌。因此，这表明 DADS 可能通过增加根系活力和光合能力以及发育来减轻番茄自毒作用，从而提高番茄的抗性和促进番茄植物生长。
