A series of novel 3-(difluoromethyl)-1-methyl-1H-pyrazole-4-carboxylic acid amides were synthesized and their activities were tested against seven phytopathogenic fungi by an in vitro mycelia growth inhibition assay. Most of them displayed moderate to excellent activities. Among them N-(2-(5-bromo-1H-indazol-1-yl)phenyl)-3-(difluoro-methyl)-1-methyl-1H-pyrazole-4-carboxamide (9m) exhibited higher antifungal activity against the seven phytopathogenic fungi than boscalid. Topomer CoMFA was employed to develop a three-dimensional quantitative structure-activity relationship model for the compounds. In molecular docking, the carbonyl oxygen atom of 9m could form hydrogen bonds towards the hydroxyl of TYR58 and TRP173 on SDH.

Drought (D) and heat (H) are the two major abiotic stresses hindering cereal crop growth and productivity, either singly or in combination (D/+H), by imposing various negative impacts on plant physiological and biochemical processes. Consequently, this decreases overall cereal crop production and impacts global food availability and human nutrition. To achieve global food and nutrition security vis-a-vis global climate change, deployment of new strategies for enhancing crop D/+H stress tolerance and higher nutritive value in cereals is imperative. This depends on first gaining a mechanistic understanding of the mechanisms underlying D/+H stress response. Meanwhile, functional genomics has revealed several stress-related genes that have been successfully used in target-gene approach to generate stress-tolerant cultivars and sustain crop productivity over the past decades. However, the fast-changing climate, coupled with the complexity and multigenic nature of D/+H tolerance suggest that single-gene/trait targeting may not suffice in improving such traits. Hence, in this review-cum-perspective, we advance that targeted multiple-gene or metabolic pathway manipulation could represent the most effective approach for improving D/+H stress tolerance. First, we highlight the impact of D/+H stress on cereal crops, and the elaborate plant physiological and molecular responses. We then discuss how key primary metabolism- and secondary metabolism-related metabolic pathways, including carbon metabolism, starch metabolism, phenylpropanoid biosynthesis, γ-aminobutyric acid (GABA) biosynthesis, and phytohormone biosynthesis and signaling can be modified using modern molecular biotechnology approaches such as CRISPR-Cas9 system and synthetic biology (Synbio) to enhance D/+H tolerance in cereal crops. Understandably, several bottlenecks hinder metabolic pathway modification, including those related to feedback regulation, gene functional annotation, complex crosstalk between pathways, and metabolomics data and spatiotemporal gene expressions analyses. Nonetheless, recent advances in molecular biotechnology, genome-editing, single-cell metabolomics, and data annotation and analysis approaches, when integrated, offer unprecedented opportunities for pathway engineering for enhancing crop D/+H stress tolerance and improved yield. Especially, Synbio-based strategies will accelerate the development of climate resilient and nutrient-dense cereals, critical for achieving global food security and combating malnutrition.

Since the last glacial maximum, the Earth has experienced drastic climate changes. However, with the advent of the Industrial Revolution, human activities have abruptly intensified, altering the planet’s climate patterns. Climate models predict that over the next hundred years, the globe will experience even more drastic changes than those observed in the past 20,000 years. Understanding how plants adapt to environmental changes has thus become a critical research priority. Currently, evidence suggests that plants adapt to environmental changes primarily through two distinct pathways: one mediated by genetic variation and the other involving the direct or indirect participation of epigenetic modifications. Given the unprecedented rate of contemporary climate change, epigenetic mechanisms may exert a more immediate and flexible influence than genetic modifications. Epigenetics, including DNA methylation, histone modification, and non-coding RNA, plays an important role in the post-transcriptional regulation process and affects the growth and development of plants, as well as their responses to environmental changes. In this review, we synthesize current knowledge on the epigenetic mechanisms underlying plant responses to environmental changes and examine the dynamic interplay between epigenetic regulation and environmental stimuli, aiming to provide insights into enhancing the tolerance of plants to environmental stress factors.

White clover (Trifolium repens L.) is an important lawngrass of good quality. Sequence transcriptome analysis was performed at the vegetative and flowering stages using high-throughput sequencing technology to investigate the genetic basis of secondary metabolite synthesis in white clover. The results showed that the number of upregulated genes increased significantly in the flowering stage compared to the vegetative stage. Through Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment and transcriptome analyses, we found that flavonoid and terpenoid synthesis pathways affected the growth and development of white clover. Expression of the DXP terpenoid synthesis pathway was higher at the vegetative stage than at the flowering stage. Analysis of the major pathways of flavonoid synthesis showed that the expression of flavonoid synthesis genes significantly increased at the flowering stage. To further verify the function of CHS, a key gene in the flavonoid synthesis pathway, we carried out a transgenic analysis of CHS in white clover. This study showed that CHS gene expression and flavonoid content significantly increased in transgenic tobacco. These results provide a solid theoretical basis for future research on the growth and development of white clover and breeding.