College of Grassland Science and Technology, China Agricultural University, Beijing 100193, China.
Molecules. 2022 Oct 28;27(21):7347. doi: 10.3390/molecules27217347.
The inclination toward natural products has led to the onset of the discovery of new bioactive metabolites that could be targeted for specific therapeutic or agronomic applications. Despite increasing knowledge coming to light of allelochemicals as leads for new herbicides, relatively little is known about the mode of action of allelochemical-based herbicides on herbicide-resistant weeds. Cyanamide is an allelochemical produced by hairy vetch ( Roth.). This study aimed to detect the toxicity of cyanamide to alfalfa and amaranth. Seed germination experiments were carried out by the filter paper culture, and the seedling growth inhibition experiment was carried out by spraying alfalfa ( L.) and amaranth ( L.) seedlings with cyanamide. The results showed that when the concentration of cyanamide was 0.1 g·L, the germination of amaranth seeds could be completely inhibited without affecting the germination of alfalfa seeds. At the concentration of 0.5 g·L, cyanamide could significantly inhibit the growth of the root and stem of amaranth seedlings but did not affect the growth of alfalfa. This effect was associated with the induction of oxidative stress. The ascorbate peroxidase (APX) and catalase (CAT) activity of amaranth decreased by 6.828 U/g FW and 290.784 U/g FW, respectively. The malondialdehyde (MDA) content, peroxidase (POD), and superoxide dismutase (SOD) activity of amaranth firstly increased and then decreased with the increasing concentration of CA. These enzyme activities of amaranth changed more than that of alfalfa. Activities of the antioxidant enzymes APX, CAT, POD, and SOD and the content of MDA varied dramatically, thereby demonstrating the great influence of reactive oxygen species upon identified allelochemical exposure. In addition, cyanamide can also inhibit the production of chlorophyll, thereby affecting the growth of plants. From the above experiments, we know that cyanamide can inhibit the growth of amaranth in alfalfa fields. Thus, the changes caused by cyanamide described herein can contribute to a better understanding of the actions of allelochemical and the potential use of cyanamide in the production of bioherbicides.
对天然产物的倾向导致了新的生物活性代谢物的发现，这些代谢物可以作为特定治疗或农业应用的靶点。尽管越来越多的化感物质作为新型除草剂的先导化合物被发现，但对于化感物质除草剂对除草剂抗性杂草的作用模式知之甚少。氰胺是毛野豌豆（Roth.）产生的化感物质。本研究旨在检测氰胺对紫花苜蓿和苋菜的毒性。通过滤纸培养进行种子萌发实验，通过喷洒紫花苜蓿（L.）和苋菜（L.）幼苗进行幼苗生长抑制实验。结果表明，当氰胺浓度为 0.1 g·L 时，完全可以抑制苋菜种子的萌发，而不影响紫花苜蓿种子的萌发。在 0.5 g·L 的浓度下，氰胺能显著抑制苋菜幼苗根和茎的生长，但不影响紫花苜蓿的生长。这种作用与诱导氧化应激有关。苋菜的抗坏血酸过氧化物酶（APX）和过氧化氢酶（CAT）活性分别降低了 6.828 U/g FW 和 290.784 U/g FW。苋菜的丙二醛（MDA）含量、过氧化物酶（POD）和超氧化物歧化酶（SOD）活性先增加后减少，随着 CA 浓度的增加而增加。苋菜的这些酶活性变化比紫花苜蓿更为明显。抗氧化酶 APX、CAT、POD 和 SOD 的活性以及 MDA 的含量变化剧烈，从而证明了活性氧对鉴定的化感物质暴露的巨大影响。此外，氰胺还可以抑制叶绿素的产生，从而影响植物的生长。从以上实验可知，氰胺可以抑制苋菜在紫花苜蓿田中的生长。因此，本文所述的氰胺引起的变化有助于更好地理解化感物质的作用以及氰胺在生物除草剂生产中的潜在用途。
