在这项研究中,在幼苗阶段,使用埃皮克洛·布罗米科拉感染(E)和未感染(E-)的野生大麦(大麦)进行水培实验。各种属性,如内生真菌对野生大麦生长发育的影响,镉(Cd)和矿质元素(Ca,Mg,Fe,Mn,Cu,Zn),亚细胞分布,并研究了CdCl2胁迫下的化学形态。结果表明,在Cd胁迫下,真菌内生性显著降低了植物根系的Ca含量和百分比。根的铁和锰含量,可溶性部分的矿物元素含量,果胶酸或蛋白质螯合状态的茎响应真菌内生性而显着增加。植物内生菌有助于Cd2进入植物;并降低了根中Ca-Fe和Ca-Mn的正相关。此外,它也降低了可溶性成分Cd-Cu的相关性,Cd-Ca,根中的Cd-Mg,茎中果胶酸或蛋白质螯合镉与矿质元素呈负相关,增加宿主对矿质元素的吸光度。总之,真菌内生性调节矿质元素的浓度和分布,同时储存更多的Cd2+以抵抗Cd应力造成的损伤。该研究为揭示内生真菌共生体对Cd的耐受机制奠定了基础。
本研究首次研究了真菌内生对重金属胁迫下植物必需矿质元素的影响,填补了现有研究的空白。该研究有助于揭示内生真菌提高寄主对重金属的耐受性的机理,为草类-内生真菌共生体改良重金属污染土壤作为生态草提供依据。
In this study, wild barley (Hordeum brevisubulatum) infected (E+) and uninfected (E-) by Epichloë bromicola were used for hydroponic experiments during the seedling stage. Various attributes, such as the effect of fungal endophyte on the growth and development of wild barley, the absorption of cadmium (Cd) and mineral elements (Ca, Mg, Fe, Mn, Cu, Zn),
subcellular distribution, and chemical forms were investigated under CdCl2 stress. The results showed that the fungal endophy significantly reduced the Ca content and percentage of plant roots under Cd stress. The Fe and Mn content of roots, the mineral element content of soluble fractions, and the stems in the pectin acid or protein-chelated state increased significantly in response to fungal endophy. Epichloë endophyte helped Cd2+ to enter into plants; and reduced the positive correlation of Ca-Fe and Ca-Mn in roots. In addition, it also decreased the correlation of soluble components Cd-Cu, Cd-Ca, Cd-Mg in roots, and the negative correlation between pectin acid or protein-chelated Cd in stems and mineral elements, to increase the absorbance of host for mineral elements. In conclusion, fungal endophy regulated the concentration and distribution of mineral elements, while storing more Cd2+ to resist the damage caused by Cd stress. The study could provide a ground for revealing the Cd tolerance mechanism of endophytic fungal symbionts.
The present study is the first to study the effect of fungal endophy on essential mineral elements of plants under heavy metal stress, filling a gap in the existing research. The study could be helpful to reveal the mechanism of endophytic fungi to improve the host\'s tolerance to heavy metals and provide a foundation for the grass-endophyte symbionts to improve heavy metal-contaminated soils as ecological grasses.