Dissecting the Role of Promoters of Pathogen-sensitive Genes in Plant Defense

Plant Promoters and Terminators for High-Precision Bioengineering

High-precision bioengineering and synthetic biology require fine-tuning gene expression at both transcriptional and posttranscriptional levels. Gene transcription is tightly regulated by promoters and terminators. Promoters determine the timing, tissues and cells, and levels of the expression of genes. Terminators mediate transcription termination of genes and affect mRNA levels posttranscriptionally, e.g., the 3'-end processing, stability, translation efficiency, and nuclear to cytoplasmic export of mRNAs. The promoter and terminator combination affects gene expression. In the present article, we review the function and features of plant core promoters, proximal and distal promoters, and terminators, and their effects on and benchmarking strategies for regulating gene expression.

Recent genome-wide replication promoted expansion and functional differentiation of the JAZs in soybeans

Jasmonate Zim-domain (JAZ) protein is an inhibitor of the jasmonate (JA) signal transduction pathway, and plays an important role in regulating plant growth, development, and defense. However, there have been few studies on its function under environmental stress in soybeans. In this study, a total of 275 JAZs protein-coding genes were identified in 29 soybean genomes. SoyC13 contained the least JAZ family members (26 JAZs), which was twice as high as AtJAZs. The genes are mainly generated by recent genome-wide replication (WGD), which replicated during the Late Cenozoic Ice Age. In addition, transcriptome analysis showed that the differences in gene expression patterns in the roots, stems, and leaves of the 29 cultivars at the V1 stage were not significant, but there was a significant difference among the three seed development stages. Finally, qRT-PCR results showed that GmJAZs responded the most strongly to heat stress, followed by drought and cold stress. This is consistent with the reason for their expansion and promoter analysis results. Therefore, we explored the significant role of conserved, duplicated, and neofunctionalized JAZs in the evolution of soybeans, which will contribute to the functional characterization of GmJAZ and the improvement of crops.

Comprehensive Analysis of Major Latex-Like Protein Family Genes in Cucumber (Cucumis sativus L.) and Their Potential Roles in Phytophthora Blight Resistance

Major latex-like proteins (MLPs) play crucial roles in abiotic and biotic stresses. However, little was known about this gene family in cucumbers. In this study, a total of 37 putative cucumber MLP genes were identified on a genome-wide level and classified into three groups by sequence homologous comparison with Arabidopsis thaliana. Chromosome mapping suggested that only tandem duplication occurred in evolution. The multiple regulatory cis-elements related to stress, hormone, light and growth response were found in the promoter region of these CsMLP genes, indicating that CsMLPs might be widely involved in the process of plant growth, development and various stress conditions. Transcriptome analysis indicated a strong reprogramming of MLPs expression in response to Phytophthora melonis infection in cucumber. Knockdown of CsMLP1 reduced the P. melonis tolerance, while transient overexpression of CsMLP1 improved disease tolerance in cucumber. Conversely, the silence of CsMLP5 decreased the lesion area caused by P. melonis in the cotyledons, and overexpression of CsMLP5 promoted lesion expansion. Taken together, our results provide a comprehensive basis for further mining the function of CsMLP members and will also be significant for elucidating the evolutionary relationship in cucumber.

Identification and Expression Analysis of the Solanum tuberosum StATG8 Family Associated with the WRKY Transcription Factor

Autophagy is an evolutionarily well-conserved cellular catabolic pathway in eukaryotic cells and plays an important role in cellular processes. Autophagy is regulated by autophagy-associated (ATG) proteins. Among these ATG proteins, the ubiquitin-like protein ATG8/LC3 is essential for autophagosome formation and function. In this study, the potato StATG8 family showed clade I and clade II with significantly different sequences. Expression of the StATG8 family was also increased in senescence. Interestingly, the expression of the StATG8 and other core StATG genes decreased in potato tubers as the tubers matured. The StATG8 family also responded to a variety of stresses such as heat, wounding, salicylic acid, and salt stress. We also found that some Arabidopsis WRKY transcription factors interacted with the StATG8 protein in planta. Based on group II-a WRKY, StATG8-WRKY interaction is independent of the ATG8 interacting motif (AIM) or LC3 interacting region (LIR) motif. This study showed that the StATG8 family had diverse functions in tuber maturation and multiple stress responses in potatoes. Additionally, StATG8 may have an unrelated autophagy function in the nucleus with the WRKY transcription factor.

Active and adaptive plasticity in a changing climate

Better understanding of the mechanistic basis of plant plasticity will enhance efforts to breed crops resilient to predicted climate change. However, complexity in plasticity's conceptualisation and measurement may hinder fruitful crossover of concepts between disciplines that would enable such advances. We argue active adaptive plasticity is particularly important in shaping the fitness of wild plants, representing the first line of a plant's defence to environmental change. Here, we define how this concept may be applied to crop breeding, suggest appropriate approaches to measure it in crops, and propose a refocussing on active adaptive plasticity to enhance crop resilience. We also discuss how the same concept may have wider utility, such as in ex situ plant conservation and reintroductions.