No abstract

The prevention of Botrytis cinerea infection and the study of grape seedlessness are very important for grape industries. Finding correlated regulatory genes is an important approach towards understanding their molecular mechanisms.• Ethylene responsive factor (ERF) gene family play critical roles in defence networks and the growth of plants. To date, no large-scale study of the ERF proteins associated with pathogen defence and ovule development has been performed in grape (Vitis vinifera L.). In the present study, we identified 113 ERF genes (VvERF) and named them based on their chromosome locations. The ERF genes could be divided into 11 groups based on a multiple sequence alignment and a phylogenetic comparison with homologues from Arabidopsis thaliana. Synteny analysis and Ka/Ks ratio calculation suggested that segmental and tandem duplications contributed to the expansion of the ERF gene family. The evolutionary relationships between the VvERF genes were investigated by exon-intron structure characterisation, and an analysis of the cis-acting regulatory elements in their promoters suggested potential regulation after stress or hormone treatments.• Expression profiling after infection with the fungus, B. cinerea, indicated that ERF genes function in responses to pathogen attack. In addition, the expression levels of most ERF genes were much higher during ovule development in seedless grapes, suggesting a role in ovule abortion related to seedlessness.• Taken together, these results indicate that VvERF proteins are involved in responses to Botrytis cinerea infection and in grape ovule development. This information may help guide strategies to improve grape production.

Over the past 20 years, Severe acute respiratory syndrome CoV (SARS-CoV), Middle East respiratory syndrome CoV (MERS-CoV) and severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2), have all emerged, causing severe epidemic human respiratory diseases throughout the globe. Developing broad spectrum drugs would be invaluable in responding to new emerging coronaviruses of the future and could address unmet urgent clinical needs. Main protease (M pro , also known as 3CL pro ) has a major role in the replication of a coronavirus life cycle and is one of the most important drug targets for anticoronavirus agents. We show that a natural product, noncovalent inhibitor shikonin, can pan-main protease inhibitor of SARS-CoV-2, SARS-CoV, MERS-CoV, HCoV-HKU1, HCoV-NL63 and HCoV-229E with micromolar IC 50 values. Structures of the main protease of different coronavirus genus, SARS-CoV from betacoronaviruses and HCoV-NL63 from alphacoronaviruses, were determined by X-ray crystallography and reveals that the inhibitor interacts with key active-site residues in a unique mode. The structure of the main protease inhibitor complex presents an opportunity to discover a novel series of broad-spectrum inhibitors. These data provide substantial evidence that shikonin and its derivatives may be effective against most coronaviruses, as well as emerging coronaviruses in the future. Given the importance of main protease for the coronavirus therapeutic indication, insights from these studies should accelerate the development and design of safer and more effective antiviral agents. Importance The current pandemic has created an urgent need for broad spectrum inhibitors of SARS-CoV-2. Main protease is relatively conservative compared with the spike protein and thus is one of the most promising drug targets for developing anticoronavirus agents. We have solved crystal structures of main protease of SARS-CoV and HCoV-NL63 bound to shikonin. The structures provide important insights that have broad implications for understanding the structural basis underlying enzyme activity, and can facilitate rational design of broad spectrum anticoronavirus ligands as new therapeutic agents.

Background Pinus massoniana Lamb. is the timber species with the widest distribution and the largest afforestation area in China, providing a large amount of timber, turpentine and ecological products. Seasonal drought caused by climate warming severely constrains the quality and growth of P. massoniana forests. WRKY transcription factors play an important role in plant responses to abiotic stress. In this study, the molecular mechanisms by which P. massoniana responds to drought stress were analysed based on the P. massoniana WRKY (PmWRKY) family of genes. Results Forty-three PmWRKYs are divided into three major families, 7 sub-families, and the conserved motifs are essentially the same. Among these 43 PmWRKYs express under drought stress but with different expression patterns in response to stress. PmWRKYs respond to drought stress induced by exogenous hormones of SA, ABA, and MeJA. The expression of PmWRKY6, PmWRKY10, and PmWRKY30 up-regulate in different families and tissues under drought stress, while PmWRKY22 down-regulate. Transgenetic tobaccos of PmWRKY31 are with lower malondialdehyde (MDA) content and higher proline (Pro) content than wild type (WT) tobaccos. In transgenic tobaccos of PmWRKY31, expression levels of related genes significantly improve, and drought tolerance enhance. Conclusions This study analysed the molecular biological characteristics of PmWRKYs and investigated the expression patterns and functions of PmWRKYs in response to drought stress in P. massoniana. The results of this study provide a basis for in-depth research of the molecular functions of PmWRKYs in response to drought stress.