With the frequent occurrence of extreme weather such as typhoons and rainstorms, waterlogging has become one of the most important threats to global crop growth and production. Waterlogging limits plants’ access to oxygen and light, leading to disadvantageous changes in metabolism to disturb plant growth and development. To escape the damage of hypoxia or promote the diffusion of oxygen to submerged organs, plants respond to waterlogging stress by regulating their morphological structure, photosynthesis, respiration, energy metabolism, and endogenous plant hormone biosynthesis/signal transduction. The adventitious roots (AR), aerenchyma, and stem internode are the major target structure for waterlogging adaptation. The molecular mechanism of crop survival under waterlogging conditions and the key genes related photosynthesis, reactive oxygen species (ROS) homeostasis, and ethylene signal transduction are reviewed. We also elucidated recent advances in the study of interactions between various regulatory pathways and emphasized the important role of stress memory and cross-stress mechanisms in plant response to abiotic stress, indicating the importance of epigenetic modifications. On the basis of above, the research direction and focus of plants coping with waterlogging stress in the future are proposed. This review provides rich genetic resources and a theoretical basis for improving the genetic breeding of crop resistance to waterlogging.

Cadmium (Cd) pollution severely threatens to plant development and human health. As a phytoremediation species, S. portulacastrum possesses outstanding Cd accumulation ability. S. portulacastrum seedings was cultivated with half-strength Hoagland solution with 25 mg/L of CdCl₂, with Cd-free medium as control. After 14 days, treated plant kept growing but showed a 43.4% lower growth rate and 1.3 cm shorter roots. Leaf number increased and then decreased, whereas fresh weight increased continuously. The chlorophyll a/b ratio dropped to 1.89, suppressing photosynthesis. To eliminate excess ROS, plants activated comprehensive antioxidant systems: root SOD activity hit 192.64 U/g, root POD and stem CAT activities rose 2.8- and 4.6-fold separately. Cd accumulated predominantly in roots at 622.14 mg/kg, displaying obvious tissue specificity. Transcriptome analysis revealed 2461 and 4545 leaf DEGs, 2215 and 3004 root DEGs after 7 and 14 ds Cd exposure. Combined physiological and transcriptomic data uncovered two core Cd-tolerant mechanisms: metal transporters sequester toxic Cd²⁺ in vacuoles, and antioxidant systems scavenge ROS. Hub genes of key modules were enriched in glutathione metabolism, carbon metabolism, oxidative phosphorylation, peroxisome, protein processing, endocytosis and phenylpropanoid biosynthesis pathways. RT-qPCR validated the expression of representative metal transport and antioxidant hub genes, and heterologous GPX overexpression in yeast INVSc1 verified its function in boosting Cd tolerance. This study provides theoretical support for breeding heavy metal remediation plants via genetic engineering.

External environment shapes the cold adaptation of Ophraella communa, a specialist natural enemy of the invasive common ragweed, and further affects its biological control efficacy. Our study aims to clarify the cold tolerance correlation between ragweed and leaf beetle and explore whether host cold acclimation can enhance the beetle’s low-temperature adaptability. We measured cold-resistant substances, supercooling point (SCP), and chill-coma recovery time (CCRT) of four geographic populations, and conducted indoor low-temperature acclimation of ragweed at 13 °C, 17 °C, 21 °C for 3–9 d, then fed leaf beetle with treated leaves. Results showed that cold-resistant substances in both species varied with latitude and were highly heritable. Cold acclimation can elevate sugars, trehalose, glycerol, and proline in ragweed; the cold tolerance of beetles feeding on these plants was significantly improved. We conclude that cold-resistant substances in ragweed can be trophically transferred to leaf beetle to enhance its cold hardiness, providing a new strategy to improve biocontrol in high-latitude regions.

Plants are frequently exposed to various abiotic stresses during their growth and development. S. portulacastrum possesses inherent tolerance to salinity and heavy metals, yet the underlying molecular mechanisms remain poorly understood. In this study, we performed a comprehensive analysis of S. portulacastrum by integrating full-length transcriptome sequencing and RNA sequencing (RNA-seq) under salt stress conditions. Transcriptome analysis identified 2839 and 1813 DEGs in leaves and 7328 and 754 DEGs in roots at 7 and 14 ds after NaCl treatment, respectively. Pathway enrichment analysis indicated that these DEGs were significantly enriched in pathways associated with Photosynthesis, plant hormone signal transduction, Linoleic acid metabolism, chlorophyll metabolism, and amino acid metabolism. Expression profiling showed that JAZ subfamily genes were significantly upregulated in both leaves and roots under salt and Cd stress. We cloned SpJAZ1, SpJAZ5, and SpJAZ7, and generated their overexpression lines in Arabidopsis. Physiological assays demonstrated that overexpression of SpJAZ1, SpJAZ5, and SpJAZ7 reduced hydrogen peroxide content by 29.07%, 20.62%, and 19.79%, respectively, and lowered the reduction in chlorophyll content (0.12, 0.15, and 0.17 μg/mL vs. 0.22 μg/mL). Meanwhile, proline content was increased in these lines (2.34, 2.08, and 2.05 μg/mL vs. 1.53 μg/mL), alongside enhancements in root length, lateral root number, and water content under salt stress. Importantly, these overexpression lines displayed a similar functional trend under Cd stress. Collectively, our results reveal potential crosstalk between the JA signaling pathway and stress mitigation pathways in S. portulacastrum in response to salt and Cd stresses.

AOC is a key enzyme in jasmonic acid (JA) biosynthesis and plays important roles in plant development and stress responses. However, the evolutionary characteristics and functional diversification of the AOC gene family in cotton remain poorly understood. In this study, AOC genes were identified and systematically characterized in four representative cotton species. Phylogenetic analysis revealed that cotton AOCs were mainly distributed in Clade II and Clade IV. Structural and promoter analyses indicated that cotton AOCs possess conserved Allene_ox_cyc domains but exhibit diversification in gene structures and regulatory elements. Synteny analysis revealed that tandem duplication and WGD/segmental duplication were the major driving forces underlying AOC gene family expansion in diploid and tetraploid cotton species, respectively. Expression analysis of GhAOC genes showed that GhAOC6 and its homologous gene GhAOC4 exhibited strong responses to Verticillium dahliae infection. Co-silencing of GhAOC4/6 significantly reduced cotton resistance to Verticillium wilt. Overall, this study provides new insights into the evolutionary conservation and functional diversification of the AOC gene family in cotton and identifies the highly homologous GhAOC4/6 pair as a candidate component associated with cotton resistance to Verticillium wilt.