Rice stripe mosaic virus hijacks rice heading‐related gene to promote the overwintering of its insect vector

Rice stripe mosaic virus(RSMV)is an emerging pathogen which significantly reduces rice yields in the southern region of China.It is transmitted by the leafhopper Recilia dorsalis,which overwinters in rice fields.Our field investigations revealed that RSMV infection causes delayed rice heading,resulting in a large number of green diseased plants remaining in winter rice fields.This creates a favorable environment for leafhoppers and viruses to overwinter,potentially contributing to the rapid spread and epidemic of the disease.Next,we explored the mechanism by which RSMV manipulates the developmental processes of the rice plant.A rice heading‐related E3 ubiquitin ligase,Heading date Associated Factor 1(HAF1),was found to be hijacked by the RSMV‐encoded P6.The impairment of HAF1 function affects the ubiquitination and degradation of downstream proteins,HEADING DATE 1 and EARLY FLOWERING3,leading to a delay in rice heading.Our results provide new insights into the development regulation‐based molecular interactions between virus and plant,and highlights the importance of understanding virus‐vector‐plant tripartite interactions for effective disease management strategies.

Key geodynamic processes and driving forces of Tethyan evolution

Tethys tectonic system has experienced a long-term evolution history,including multiple Wilson cycles;thus,it is an ideal target for analyzing plate tectonics and geodynamics.Tethyan evolution is typically characterized by a series of continental blocks that separated from the Gondwana in the Southern Hemisphere,drifted northward,and collided and accreted with Laurasia in the Northern Hemisphere.During this process,the successive opening and closing of multistage Tethys oceans(e.g.,Proto-Tethys,Paleo-Tethys,and Neo-Tethys)are considered core parts of the Tethyan evolution.Herein,focusing on the life cycle of an oceanic plate,four key geodynamic processes during the Tethyan evolution,namely,continental margin breakup,subduction initiation(SI),Mid-Ocean Ridge(MOR)subduction,and continental collision,were highlighted and dynamically analyzed to gather the following insights.(1)Breakup of the narrow continental margin terranes from the northern Gondwana is probably controlled by plate subduction,particularly the subduction-induced far-field stretching.The breakup of the Indian continent and the subsequent spreading of the Indian Ocean can be attributed to the interactions between multiple mantle plumes and slab drag-induced far-field stretching.(2)Continental margin terrane collision-induced subduction transference/jump is a key factor in progressive Tethyan evolution,which is driven by the combined forces of collision-induced reverse push,far-field ridge push,and mantle flow traction.Moreover,lithospheric weakening plays an important role in the occurrence of SI.(3)MOR subduction is generally accompanied by slab break-off.In case of the considerably reduced or temporary absence of slab pull,mantle flow traction may contribute to the progression of plate subduction.MOR subduction can dynamically influence the overriding and downgoing plates by producing important and diagnostic geological records.(4)The large gravitational potential energy of the Tibetan Plateau indicates that the long-lasting India-Asia continental collision requires other driving forces beyond the far-field ridge push.Further,the mantle flow traction is a good candidate that may considerably contribute to the continuous collision.The possible future SI in the northern Indian Ocean will release the sustained convergent force and cause the collapse of the Tibetan Plateau.Based on the integration of these four geodynamic processes and their driving forces,a“multienginedriving”model is proposed for the dynamics of Tethyan evolution,indicating that the multiple stages of Tethys oceanic subduction provide the main driving force for the northward drifting of continental margin terranes.However,the subducting slab pull may be considerably reduced or even lost during tectonic transitional processes,such as terrane collision or MOR subduction.In such stages,the far-field ridge push and mantle flow traction will induce the initiation of new subduction zones,driving the continuous northward convergence of the Tethys tectonic system.

三星堆遗址城墙不同维护措施下草本植物物种多样性与土壤抗冲性的关系

三星堆遗址城墙对中华文明探源工程具有重要意义。研究不同维护措施下草本植物物种多样性、根系与土壤抗冲性的关系对防止遗址城墙水土流失、发挥原生植被的水土保持作用意义重大。本研究基于样地调查,以三星堆遗址城墙的草本植物群落为研究对象,探讨了自然更新、种植、弃耕、灌木去除、修剪5种维护措施下草本植物物种多样性、根系和土壤抗冲性特征及其相关性。结果表明:(1)研究区共记录草本植物103种,隶属40科81属,以菊科及禾本科植物占优,多年生草本植物居多。(2)灌木去除样地的物种多样性水平相对较高,自然更新样地次之,再次是修剪样地和种植样地,弃耕样地物种多样性水平显著低于其余样地(P<0.05)。(3)灌木去除样地和自然更新样地的土壤抗冲系数(分别为138.86 L/g和118.31 L/g,二者无显著差异(P>0.05))显著高于其余类型(P<0.05)。除根长密度外,灌木去除样地的根表面积密度、根体积密度和平均根径均显著高于其他类型(P<0.05)。(4)4种多样性指数(Shannon-Wiener多样性指数、Simpson优势度指数、物种丰富度指数、Pielou均匀度指数)、根长密度、平均根径、分叉数均与土壤抗冲系数极显著正相关(P<0.01);根表面积密度、根体积密度与土壤抗冲系数亦显著正相关(P<0.05)。综上,灌木去除样地与自然更新样地的草本植物物种多样性指数、根系参数与土壤抗冲性较好。结合城墙区域的植被特点和遗址保护的原真性,建议实行以自然更新为主的原生境保护措施,必要时辅以如灌木去除、修剪等维护措施,有效提升物种多样性和土壤抗冲性,促进三星堆遗址城墙植被的可持续发展和原生态展现。