College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China.
J Agric Food Chem. 2010 Dec 22;58(24):12710-6. doi: 10.1021/jf1032608. Epub 2010 Nov 18.
Despite increasing knowledge of 2,4-dihydroxy-7-methoxy-1,4-benzoxazin-3-one (DIMBOA) and 6-methoxy-benzoxazolin-2-one (MBOA) as allelochemicals involved in the defense of wheat against pests, relatively little is known about their levels in the rhizosphere and interactions with the soil microbial community. This study quantified DIMBOA and MBOA in the wheat rhizosphere and analyzed the soil microbial community structure. MBOA rather than DIMBAO was found in the wheat rhizosphere, and its concentration varied with cultivars, plant densities, and growth conditions. Wheat could detect the presence of competing weeds and respond by increased MBOA in the rhizosphere. There was a linear positive relationship between the MBOA level in the wheat rhizosphere and soil fungi/bacteria. When DIMBOA was applied to soil, yielding MBOA increased soil fungi. There were different phospholipid fatty acid (PLFA) patterns in soil incubated with DIMBOA and MBOA. These results suggested that DIMBOA and MBOA could affect the soil microbial community structure to their advantage through the change in fungi populations.
尽管人们对 2,4-二羟基-7-甲氧基-1,4-苯并恶嗪-3-酮（DIMBOA）和 6-甲氧基苯并恶唑啉-2-酮（MBOA）作为参与小麦抵御害虫的化感物质有了更多的了解，但对它们在根际中的水平及其与土壤微生物群落的相互作用相对知之甚少。本研究定量测定了小麦根际中的 DIMBOA 和 MBOA，并分析了土壤微生物群落结构。研究发现，MBOA 而不是 DIMBOA 存在于小麦根际中，其浓度随品种、植物密度和生长条件而异。小麦可以检测到竞争杂草的存在，并通过增加根际中的 MBOA 做出反应。小麦根际中 MBOA 水平与土壤真菌/细菌呈线性正相关。当 DIMBOA 施加到土壤中时，产生的 MBOA 增加了土壤真菌。用 DIMBOA 和 MBOA 孵育的土壤中存在不同的磷脂脂肪酸（PLFA）模式。这些结果表明，DIMBOA 和 MBOA 可以通过改变真菌种群，从而改变土壤微生物群落结构，使其受益。
