The soil microbiome reduces Striga infection of sorghum by modulation of host-derived signaling molecules and root development. The soil microbiome reduces Striga infection of sorghum

Sorghum bicolor is one of the most important cereals in the world and a staple crop for smallholder famers in sub-Saharan Africa. However approximately 20% of sorghum yield is annually lost on the African continent due to infestation with the root parasitic weed Striga hermonthica. Existing Striga management strategies often show an inconsistent to low efficacy. Hence, novel and integrated approaches are needed as an alternative strategy. Here, we demonstrate that the soil microbiome suppresses Striga infection in sorghum. We associate this suppression with microbiome-mediated induction of root endodermal suberization and aerenchyma formation, and depletion of haustorium inducing factors (HIFs), root exudate compounds that are critical for the initial stages of Striga infection. We further identify microbial taxa associated with reduced Striga infection with concomitant changes in root cellular anatomy and differentiation as well as HIF degradation. Our study describes novel microbiome-mediated mechanisms of Striga suppression, encompassing repression of haustorium formation and induction of physical barriers in the host root tissue. These findings open new avenues to broaden the effectiveness of Striga management practices.

双色高粱（Sorghum bicolor）是全球最重要的谷类作物之一，同时也是撒哈拉以南非洲小农户的主粮作物。然而，非洲大陆每年约有20%的高粱产量因根寄生杂草非洲独脚金（Striga hermonthica）的侵染而损失。现有的独脚金防治策略往往效果不稳定甚至低效，因此亟需开发新型综合防治手段作为替代方案。本研究证实，土壤微生物组可抑制高粱受非洲独脚金侵染。我们发现该抑制效应与微生物组介导的根内皮层栓质化及通气组织形成、吸器诱导因子（haustorium inducing factors, HIFs）的耗竭密切相关——这类根系分泌物化合物是独脚金侵染初始阶段的关键因子。我们进一步鉴定出与独脚金侵染减轻相关的微生物类群，同时伴随根系细胞解剖结构与分化状态的改变，以及HIFs的降解。本研究揭示了微生物组介导的独脚金抑制新机制，涵盖对吸器形成的抑制以及宿主根系组织物理屏障的诱导。上述发现为提升独脚金防治实践的有效性开辟了全新途径。