Zhou Xijie, Xiao Yunxing, Ma Danwei, Xie Yusi, Wang Yu, Zhang Hong, Wang Yanan
College of Life Science, Sichuan Normal University, Chengdu, China.
Front Plant Sci. 2023 Mar 6;14:1124139. doi: 10.3389/fpls.2023.1124139. eCollection 2023.
The competitive strategies of plants play a crucial role in their growth. Allelopathy is one of the weapons that plants use to improve their competitive advantage.
In order to explore the competitive strategy of a poisonous weed Benth. () on the Qinghai-Tibet Plateau (QTP), the effects of decomposing substances of on growth, root border cells (RBCs) characteristics of highland crop highland barley ( L.), and soil environment were determined.
The decomposing allelopathic effect of on the germination and seedling growth of highland barley mainly occurred in the early stage of decomposing. The allelopathic effects were mainly on seed germination and root growth of highland barley. After treatment with its decomposing solution, the RBC's mucilage layer of highland barley thickened, and the RBC's activity decreased or even apoptosis compared with the control. However, only the above-ground part of the treatment group showed a significant difference. The effects of decomposed substances on the soil environment were evaluated from soil physicochemical properties and bacterial community. The results showed that soil bacteria varied greatly in the early stage of decomposion under different concentrations of . In addition, decomposing substances increased the soil nutrient content, extracellular enzyme activities, and bacterial community diversity. In the process of decomposition, the bacterial community structure changed constantly, but Actinobacteriota was always the dominant phylum.
These results indicated that might adopt the following two strategies to help it gain an advantage in the competition: 1. Release allelochemicals that interfere with the defense function of surrounding plants and directly inhibit the growth and development of surrounding plants. 2. By changing the physical and chemical properties of soil and extracellular enzyme activity, residual plant decomposition can stimulate soil microbial activity, improve soil nutrition status, and create a more suitable soil environment for growth.
植物的竞争策略在其生长过程中起着至关重要的作用。化感作用是植物用来提高其竞争优势的武器之一。
为了探究青藏高原一种有毒杂草（具体杂草名称未给出）的竞争策略，测定了该杂草分解物质对高原作物青稞生长、根边缘细胞（RBCs）特征以及土壤环境的影响。
该杂草分解物质对青稞种子萌发和幼苗生长的化感作用主要发生在分解前期。化感作用主要影响青稞种子萌发和根系生长。用其分解液处理后，青稞根边缘细胞的黏液层增厚，与对照相比，根边缘细胞活性降低甚至凋亡。然而，仅处理组地上部分表现出显著差异。从土壤理化性质和细菌群落方面评估了该杂草分解物质对土壤环境的影响。结果表明，在不同浓度该杂草分解物质作用下，土壤细菌在分解前期变化很大。此外，该杂草分解物质增加了土壤养分含量、胞外酶活性以及细菌群落多样性。在分解过程中，细菌群落结构不断变化，但放线菌门始终是优势菌门。
这些结果表明，该杂草可能采取以下两种策略来帮助其在竞争中获得优势：1. 释放化感物质，干扰周围植物的防御功能，直接抑制周围植物的生长发育。2. 通过改变土壤理化性质和胞外酶活性，残留植物分解可刺激土壤微生物活性，改善土壤营养状况，为生长创造更适宜的土壤环境。
