Importin-αs are required for the nuclear localization and function of the Plasmopara viticola effector PvAVH53

Plant pathogenic oomycetes deliver a troop of effector proteins into the nucleus of host cells to manipulate plant cellular immunity and promote colonization.Recently,researchers have focused on identifying how effectors are transferred into the host cell nucleus,as well as the identity of the nuclear targets.In this study,we found that the RxLR effector PvAVH53 from the grapevine(Vitis vinifera)oomycete pathogen Plasmopara viticola physically interacts with grapevine nuclear import factor importin alphas(VvImpαand VvImpα4),localizes to the nucleus and triggers cell death when transiently expressed in tobacco(Nicotiana benthamiana)cells.Deletion of a nuclear localization signal(NLS)sequence from PvAVH53 or addition of a nuclear export signal(NES)sequence disrupted the nuclear localization of PvAVH53 and attenuated its ability to trigger cell death.Suppression of two tobacco importin-αgenes,namely,NbImp-α1 and NbImp-α2,by virus-induced gene silencing(VIGS)also disrupted the nuclear localization and ability of PvAVH53 to induce cell death.Likewise,we transiently silenced the expression of VvImpα/α4 in grape through CRISPR/Cas13a,which has been reported to target RNA in vivo.Finally,we found that attenuating the expression of the Importin-αs genes resulted in increased susceptibility to the oomycete pathogen Phytophthora capsici in N.benthamiana and P.viticola in V.vinifera.Our results demonstrate that importin-αs are required for the nuclear localization and function of PvAVH53 and are essential for host innate immunity.The findings provide insight into the functions of importin-αs in grapevine against downy mildew.

The slope creep law for a soft rock in an open-pit mine in the Gobi region of Xinjiang, China

The lithology of the strata in the Gobi region of the Xinjiang autonomous region of China is mainly composed of mudstone,silty mudstone,and other soft rocks.Because of the low strength of the rock mass and the serious effects of physical weathering in this area,the slope stability in open-pit mines is poor,and creep deformation and instability can readily occur.Taking the Dananhu No.2 open-pit mine as a typical example,the creep test of a mudstone sample under different stress levels was studied.Then,based on a bottom friction experiment and a FLAC3D numerical simulation,the deformation and failure processes of the slope were analyzed.The stress–displacement curve and the displacement–time curve for the monitoring points were plotted to obtain the relationship between the stress and displacement for the slope of the soft rock.The results showed that the long-term strength of the mudstone was between 8.0 and 8.8 MPa,and that stable creep occurred when the slope was under low stress.The potential failure mode for this type of slope is that the front edge creeps along the weak layer and then a crack is formed at the trailing edge of the slope.When the crack penetrates the weak layer,cutting bedding and bedding sliding occur.The deformation process of the stable creep slope includes an initial deformation stage,an initial creep stage,a constant velocity creep stage and a deceleration creep stage.

Identification of long non-coding RNAs in response to downy mildew stress in grape

The importance of long non-coding RNA in plants has been reported more frequently in recent years,but there has been few specific reports on lncRNAs in grape,especially in terms of disease resistance.We performed RNA-seq on grape leaves of two species(Vitis piasezkii accession Liuba-8,Vitis vinifera cultivar Pinot Noir)sampled at six time points after inoculation,and 4011 possible lncRNAs were identified.The characteristics of grape lncRNAs were analyzed,and it was found that lncRNAs showed relatively consistent characteristics with the reported lncRNAs in model plants.3,643 lncRNAs were predicted that have cis-regulatory effects on 6,622 protein-coding genes and 91 DElncRNAs were revealed to be coexpressed with its trans-regulated coding genes.One hundred and seventeen grape microRNAs were predicted to potentially target 184 lncRNAs and six lncRNAs were predicted to be endogenous targeting mimics of 15 microRNAs,among which some miRNAs have been reported in grape disease resistance.At six time points,LncRNAs showed different expression levels and different expression patterns in two species,suggesting that lncRNAs may have a certain regulatory effect on resistance to downy mildew in grape.Finally,a lncRNA MSTRG.12742.1 which may play a positive role in grape downy mildew resistance was verified by transient transformation.Its potential target gene,VIT_204s0008g02671.1,encodes cryptochrome DASH which may regulate stomatal opening and closing of plant leaves.In this study,we provided the systematic identification of lncRNAs in the course of downy mildew of grape,laying a foundation for further studies on downy mildew and lncRNAs of grape in the future.