Comprehensive transcriptome analysis reveals heat-responsive genes in flowering Chinese cabbage (Brassica campestris L. ssp. chinensis) using RNA sequencing

Creating Climate-Resilient Crops by Increasing Drought, Heat, and Salt Tolerance

Over the years, the changes in the agriculture industry have been inevitable, considering the need to feed the growing population. As the world population continues to grow, food security has become challenged. Resources such as arable land and freshwater have become scarce due to quick urbanization in developing countries and anthropologic activities; expanding agricultural production areas is not an option. Environmental and climatic factors such as drought, heat, and salt stresses pose serious threats to food production worldwide. Therefore, the need to utilize the remaining arable land and water effectively and efficiently and to maximize the yield to support the increasing food demand has become crucial. It is essential to develop climate-resilient crops that will outperform traditional crops under any abiotic stress conditions such as heat, drought, and salt, as well as these stresses in any combinations. This review provides a glimpse of how plant breeding in agriculture has evolved to overcome the harsh environmental conditions and what the future would be like.

Uncovering the transcriptional responses of tobacco (Nicotiana tabacum L.) roots to Ralstonia solanacearum infection: a comparative study of resistant and susceptible cultivars

BACKGROUND

Tobacco bacterial wilt (TBW) caused by Ralstonia solanacearum is the most serious soil-borne disease of tobacco that significantly reduces crop yield. However, the limited availability of resistance in tobacco hinders breeding efforts for this disease.

RESULTS

In this study, we conducted hydroponic experiments for the root expression profiles of D101 (resistant) and Honghuadajinyuan (susceptible) cultivars in response to BW infection at 0 h, 6 h, 1 d, 3 d, and 7d to explore the defense mechanisms of BW resistance in tobacco. As a result, 20,711 and 16,663 (total: 23,568) differentially expressed genes (DEGs) were identified in the resistant and susceptible cultivars, respectively. In brief, at 6 h, 1 d, 3 d, and 7 d, the resistant cultivar showed upregulation of 1553, 1124, 2583, and 7512 genes, while the susceptible cultivar showed downregulation of 1213, 1295, 813, and 7735 genes. Similarly, across these time points, the resistant cultivar had downregulation of 1034, 749, 1686, and 11,086 genes, whereas the susceptible cultivar had upregulation of 1953, 1790, 2334, and 6380 genes. The resistant cultivar had more up-regulated genes at 3 d and 7 d than the susceptible cultivar, indicating that the resistant cultivar has a more robust defense response against the pathogen. The GO and KEGG enrichment analysis showed that these genes are involved in responses to oxidative stress, plant-pathogen interactions, cell walls, glutathione and phenylalanine metabolism, and plant hormone signal transduction. Among the DEGs, 239 potential candidate genes were detected, including 49 phenylpropane/flavonoids pathway-associated, 45 glutathione metabolic pathway-associated, 47 WRKY, 48 ERFs, eight ARFs, 26 pathogenesis-related genes (PRs), and 14 short-chain dehydrogenase/reductase genes. In addition, two highly expressed novel genes (MSTRG.61386-R1B-17 and MSTRG.61568) encoding nucleotide-binding site leucine-rich repeat (NBS-LRR) proteins were identified in both cultivars at 7 d.

CONCLUSIONS

This study revealed significant enrichment of DEGs in GO and KEGG terms linked to glutathione, flavonoids, and phenylpropane pathways, indicating the potential role of glutathione and flavonoids in early BW resistance in tobacco roots. These findings offer fundamental insight for further exploration of the genetic architecture and molecular mechanisms of BW resistance in tobacco and solanaceous plants at the molecular level.

Chlorate-induced molecular floral transition revealed by transcriptomes

Flowering in off-season longan (Dimocarpus longan L.) can be induced effectively by the application of potassium chlorate (KClO₃), but the mechanism of the physiological induction is largely unknown to decipher its mechanism and identify genes potentially regulating the process, and comparative analysis via RNA-Seq was performed between vegetative and KClO₃-induced floral buds. A total of 18,649 differentially expressed genes (DEGs) were identified between control and treated samples. Gene ontology and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis revealed that DEGs related to plant hormone signal transduction, mitogen-activated protein kinase (MAPK) signaling pathway, starch and sucrose metabolism, and phenylpropanoid biosynthesis were enriched in our data. A total of 29 flowering-related DEGs were identified in our study, such as APETALA1 (AP1), APETALA2 (AP2), AUXIN RESPONSE FACTOR 3/ETTIN (ARF3), SQUAMOSA PROMOTER BINDING PROTEIN-LIKE 8 (SPL8), AGAMOUS (AG), and others. The upregulation of AP2 and SPL genes indicates that the age-related pathway is activated and influences the floral induction in KClO₃-induced longan floral buds by coordinated regulation of genes related to AP1, AG, and ARF3. This study provides a valuable resource for studying molecular mechanisms underlying chlorate-induced floral transition in off-season longan, which may benefit the development and production of off-season tropical/subtropical fruit trees.