查看更多>>摘要：Jasmonates(JAs),a class of lipid-derived stress hormones,play a crucial role across an array of plant phys-iological processes and stress responses.Although JA signaling is thought to rely predominantly on the degradation of specific JAZ proteins by SCFCOI1,it remains unclear whether other pathways are involved in the regulation of JAZ protein stability.Here,we report that PUB22,a plant U-box type E3 ubiquitin ligase,plays a critical role in the regulation of plant resistance against Helicoverpa armigera and other JA re-sponses in tomato.Whereas COI1 physically interacts with JAZ1/2/5/7,PUB22 physically interacts with JAZ1/3/4/6.PUB22 ubiquitinates JAZ4 to promote its degradation via the 26S proteasome pathway.Impor-tantly,we observed that pub22 mutants showreduced resistance to H.armigera,whereasjaz4 single mu-tants and jaz1 jaz3 jaz4 jaz6 quadruple mutants have enhanced resistance.The hypersensitivity of pub22 mutants to herbivores could be partially rescued by JAZ4 mutation.Moreover,we found that expression of PUB22 can be transcriptionally activated by MYC2,thus forming a positive feedback circuit in JA signaling.We noticed that the PUB22-JAZ4 module also regulates other JA responses,including defense against B.cinerea,inhibition of root elongation,and anthocyanin accumulation.Taken together,these re-sults indicate that PUB22 plays a crucial role in plant growth and defense responses,together with COI1-regulated JA signaling,by targeting specific JAZs.
查看更多>>摘要：The infection of host plants by many different viruses causes reactive oxygen species(ROS)accumulation and yellowing symptoms,but the mechanisms through which plant viruses counteract ROS-mediated im-munity to facilitate infection and symptom development have not been fully elucidated.Most plant viruses are transmitted by insect vectors in the field,but the molecular mechanisms underlying virus-host-insect interactions are unclear.In this study,we investigated the interactions among wheat,barley yellow dwarf virus(BYDV),and its aphid vector and found that the BYDV movement protein(MP)interacts with both wheat catalases(CATs)and the 26S proteasome ubiquitin receptor non-ATPase regulatory subunit 2 homo-log(PSMD2)to facilitate the 26S proteasome-mediated degradation of CATs,promoting viral infection,dis-ease symptom development,and aphid transmission.Overexpression of the BYDV MP gene in wheat enhanced the degradation of CATs,which leading to increased accumulation of ROS and thereby enhanced viral infection.Interestingly,transgenic wheat lines overexpressing BYDV MP showed significantly reduced proliferation of wingless aphids and an increased number of winged aphids.Consistent with this observation,silencing of CAT genes also enhanced viral accumulation and reduced the proliferation of wingless aphids but increased the occurrence of winged aphids.In contrast,transgenic wheat plants overexpressing TaCAT1 exhibited the opposite changes and showed increases in grain size and weight upon infection with BYDV.Biochemical assays demonstrated that BYDV MP interacts with PSMD2 and promotes 26S proteasome-mediated degradation of TaCAT1 likely in a ubiquitination-independent manner.Collectively,our study reveals a molecular mechanism by which a plant virus manipulates the ROS production system of host plants to facilitate viral infection and transmission,shedding new light on the sophisticated interactions among viruses,host plants,and insect vectors.
查看更多>>摘要：Hormone-activated proteolysis is a recurring theme of plant hormone signaling mechanisms.In strigolac-tone signaling,the enzyme receptor DWARF14(D14)and an F-box protein,MORE AXILLARY GROWTH2(MAX2),mark SUPPRESSOR OF MAX21-LIKE(SMXL)family proteins SMXL6,SMXL7,and SMXL8 for rapid degradation.Removal of these transcriptional corepressors initiates downstream growth responses.The homologous proteins SMXL3,SMXL4,and SMXL5,however,are resistant to MAX2-mediated degradation.We discovered that the smxl4 smxl5 mutant has enhanced responses to strigolactone.SMXL5 attenuates strigolactone signaling by interfering with AtD14-SMXL7 interactions.SMXL5 interacts with AtD14 and SMXL7,providing two possible ways to inhibit SMXL7 degradation.SMXL5 function is partially dependent on an ethylene-responsive-element binding-factor-associated amphiphilic repression(EAR)motif,which typically mediates interactions with the TOPLESS family of transcriptional corepressors.However,we found that loss of the EAR motif reduces SMXL5-SMXL7 interactions and the attenuation of strigolactone signaling by SMXL5.We hypothesize that integration of SMXL5 into heteromeric SMXL complexes reduces the susceptibility of SMXL6/7/8 proteins to strigolactone-activated degradation and that the EAR motif pro-motes the formation or stability of these complexes.This mechanism may provide a way to spatially or temporally fine-tune strigolactone signaling through the regulation of SMXL5 expression or translation.
查看更多>>摘要：Constructing inbred lines for self-incompatible species and species with long generation times is chal-lenging,making the use of F1 outcross/segregating populations the main strategy for genetic studies of such species.However,there is a lack of dedicated algorithms/tools for rapid quantitative trait locus(QTL)mapping using the F1 populations.To this end,we have designed and developed an algorithm/tool called OcBSA specifically for QTL mapping of F1 populations.OcBSA transforms the four-haplotype inher-itance problem from the two heterozygous diploid parents of the F1 population into the two-haplotype in-heritance problem common in current genetic studies by removing the two haplotypes from the heterozy-gous parent that do not contribute to phenotype segregation in the F1 population.Testing of OcBSA on 1800 simulated F1 populations demonstrated its advantages over other currently available tools in terms of sensitivity and accuracy.In addition,the broad applicability of OcBSA was validated by QTL mapping using seven reported F1 populations of apple,pear,peach,citrus,grape,tea,and rice.We also used OcBSA to map the QTL for flower color in a newly constructed F1 population of potato generated in this study.The OcBSA mapping result was verified by the insertion or deletion markers to be consistent with a previ-ously reported locus harboring the ANTHOCYANIN 2 gene,which regulates potato flower color.Taken together,these results highlight the power and broad utility of OcBSA for QTL mapping using F1 populations and thus a great potential for functional gene mining in outcrossing species.For ease of use,we have developed both Windows and Linux versions of OcBSA,which are freely available at:https://gitee.com/Bioinformaticslab/OcBSA.
查看更多>>摘要：Receptor-like kinases(RLKs)are the most numerous signal transduction components in plants and play important roles in determining how different plants adapt to their ecological environments.Research on RLKs has focused mainly on a small number of typical RLK members in a few model plants.There is an ur-gent need to study the composition,distribution,and evolution of RLKs at the holistic level to increase our understanding of how RLKs assist in the ecological adaptations of different plant species.In this study,we collected the genome assemblies of 528 plant species and constructed an RLK dataset.Using this dataset,we identified and characterized 524 948 RLK family members.Each member underwent systematic topo-logical classification and was assigned a gene ID based on a unified nomenclature system.Furthermore,we identified two novel extracellular domains in some RLKs,designated Xiao and Xiang.Evolutionary anal-ysis of the RLK family revealed that the RLCK-ⅩⅦ and RLCK-Ⅻ-2 classes were present exclusively in di-cots,suggesting that diversification of RLKs between monocots and dicots may have led to differences in downstream cytoplasmic responses.We also used an interaction proteome to help empower data mining for inference of new RLK functions from a global perspective,with the ultimate goal of understanding how RLKs shape the adaptation of different plants to the environments/ecosystems.The assembled RLK data-set,together with annotations and analytical tools,forms an integrated foundation of multiomics data that is publicly accessible via the metaRLK web portal(http://metaRLK.biocloud.top).
万方数据
维普