Journal of Plant Growth Regulation最新文献

Clubroot, caused by the obligate parasite Plasmodiophora brassicae, is a serious soilborne disease that threatens many commercially valuable crops in the Brassicaceae family, including the oilseed crop canola (Brassica napus) and various vegetables. Evidence from studies analyzing hormonal profiles, transcriptomes, proteomes, mutants defective in hormone functions, and treatments of infected plants with growth regulators suggest that nearly all plant hormones are involved in or affected by the disease. However, the specific roles of individual hormones in clubroot development or resistance remain unclear. This knowledge gap is compounded by the complex regulation of hormone functions and inconsistencies across studies, likely due to variations caused by host-pathogen combinations and other factors such as environmental influences. Additionally, biotic and abiotic stress responses caused by the disease and, in some instances, pathogen proteins manipulating host hormonal metabolism add additional layers of complexity. Despite these challenges, emerging trends suggest regulatory roles for plant hormones in both disease development and host defense. In this review, we explore these patterns, aiming to elucidate the contributions of different hormones to clubroot development and associated stress responses.

Pyrazoles have a broad range of biological properties that make them potentially useful for treating tuberculosis, microbial/fungal infections, and inflammation. In this study, the pyrazole 1,3-diaryl-1H-pyrazol-5-yl)(aryl)methanone (DPAM-1) prepared via catalytic aminooxygenation increased the sensitivity of Arabidopsis to salinity stress. An RNA-seq transcriptome analysis revealed DPAM-1 increased the expression of fewer genes than the coronatine treatment that enhanced salinity stress sensitivity, suggestive of the selective mode of action of DPAM-1. The up-regulated genes included marker genes for brassinosteroid (BR) responses. The responsiveness of BR-related genes, such as CONSTITUTIVE PHOTOMORPHOGENIC DWARF, DWARF4, Small auxin-up RNA_Ac1, and for touch 4 (TCH4)/xyloglucan endotransglucosylase/hydrolase 22 (XTH22), was verified by treatments with brassinolide (BL) and brassinazole (BR biosynthesis inhibitor) and analyses involving the brassinosteroid insensitive 1–5 (bri1-5) mutant carrying a weak allele encoding BRASSINOSTEROID INSENSITIVE 1 receptor kinase under our growth conditions. Among the examined genes, the transcription of only TCH4 increased after the DPAM-1 treatment. Examinations of the bri1-5 mutant indicated that DPAM-1 did not significantly affect the sensitivity of bri1-5 plants to salinity stress, suggesting the increased salinity stress sensitivity following the DPAM-1 treatment was partly mediated by the BR signaling pathway. In the present study, the BL treatment differentially altered the salinity stress tolerance of the Columbia and Wassilewskija accessions. The contribution of BR signaling to salinity stress tolerance during the diversification of Arabidopsis accessions and the potential applicability of DPAM-1 for elucidating the interplay between BR and other phytohormones were assessed.

It is critical to improve the adaptability of plants to drought stress through exogenous addition method. This study explored the combined effects of sodium nitroprusside (SNP) and melatonin (MT) on improving drought resilience in dryland maize. We hypothesized that the joint application of SNP + MT would enhance drought resilience through both above- and below-ground interactions. Maize plants were treated with SNP, MT, and a combination of both under different water stress conditions. The combined treatment was observed to significantly improve chlorophyll contents, water use efficiency (WUE), while reducing oxidative stress markers, compared to separate treatments and controls (CK). These improvements led to enhanced plant biomass and yield productivity under the conditions of drought. Specifically, leaf chlorophyll levels increased averagely by 24.22% under well-watered (WW) conditions, and 27.94% under mild water-stressed (MWS) conditions, respectively. In addition, the content of chlorophyll b increased by 13.27 and 56.32% in WW and MWS, respectively. Particularly, the combined treatment resulted in higher WUE, lower oxidative stress, and higher nutrient content [nitrogen, phosphorus, and potassium (NPK)], contributing to improved plant growth and yield. The examination uncovered noteworthy associations (p < 0.05) between these interventions and physiological characteristics, including heightened WUE, diminished oxidative stress, and augmented nutrient content. These factors contributed to the enhancement of plant production and biomass. The research also investigated the effects of microbial biomass carbon (MBC) and microbial biomass nitrogen (MBN). Therefore, the combined application of SNP and MT can act as a promising strategy to enhance drought tolerance in maize, demonstrating a fine potential to improve crop productivity in drought-prone areas.