Stronger together: Ethylene, jasmonic acid, and MAPK signaling pathways synergistically induce camalexin synthesis for plant disease resistance

Soybean PHR1-regulated low phosphorus-responsive GmRALF22 promotes phosphate uptake by stimulating the expression of GmPTs

Phosphorus (P) is an essential macronutrient for plant growth and development. Rapid alkalisation factors (RALFs) play crucial roles in plant responses to nutrient stress. However, the functions of Glycine max RALFs (GmRALFs) under low P (LP) stress remain elusive. In this study, we first identified 27 GmRALFs in soybean and then revealed that, under LP conditions, GmRALF10, GmRALF11, and GmRALF22 were induced in both roots and leaves, whereas GmRALF5, GmRALF6, and GmRALF25 were upregulated in leaves. Furthermore, GmRALF22 was found to be the target gene of the transcription factor GmPHR1, which binds to the P1BS cis-element in the promoter of GmRALF22 via electrophoretic mobility shift assay and dual-luciferase experiments. Colonisation with Bacillus subtilis which delivers GmRALF22, increases the expression of the high-affinity phosphate (Pi) transporter genes GmPT2, GmPT11, GmPT13, and GmPT14, thus increasing the total amount of dry matter and soluble Pi in soybeans. RNA sequencing revealed that GmRALF22 alleviates LP stress by regulating the expression of jasmonic acid- (JA-), salicylic acid- (SA-), and immune-related genes. Finally, we verified that GmRALF22 was dependent on FERONIA (FER) to promote Arabidopsis primary root growth under LP conditions. In summary, the GmPHR1-GmRALF22 module positively regulates soybean tolerance to LP.

Molecular mechanisms of neutron radiation dose effects on M1 generation peas

The dose effect of radiation has long been a topic of concern, but the molecular mechanism behind it is still unclear. In this study, dried pea seeds were irradiated with 252Cf fission neutron source. Through analyzing the transcriptome and proteome of M1 generation pea (Pisum sativum L.) leaves, we studied the molecular rule and mechanism of neutron dose effect. Our results showed three important rules of global gene expression in the studied dose range. The rule closely related to the neutron absorbed dose at the transcription and translation levels is: the greater the difference in neutron absorbed dose between two radiation treatment groups, the greater the difference in differential expression between the two groups and the control group. We also obtained important sensitive metabolic pathways of neutron radiation, as well as related key genes. Furthermore, the overall molecular regulation mechanism of dose effect was revealed based on the main functional items obtained. Our research results can be applied to appropriate radiation dose estimation and agricultural production practice.

Machine Learning Phenotyping and GWAS Reveal Genetic Basis of Cd Tolerance and Absorption in Jute

Cadmium (Cd) is a dangerous environmental contaminant. Jute (Corchorus sp.) is an important natural fiber crop with strong absorption and excellent adaptability to metal-stressed environments, used in the phytoextraction of heavy metals. Understanding the genetic and molecular mechanisms underlying Cd tolerance and accumulation in plants is essential for efficient phytoremediation strategies and breeding novel Cd-tolerant cultivars. Here, machine learning (ML) and hyperspectral imaging (HSI) combining genome-wide association studies (GWAS) and RNA-seq reveal the genetic basis of Cd resistance and absorption in jute. ML needs a small number of plant phenotypes for training and can complete the plant phenotyping of large-scale populations with efficiency and accuracy greater than 90%. In particular, a candidate gene for Cd resistance (COS02g_02406) and a candidate gene (COS06g_03984) associated with Cd absorption are identified in isoflavonoid biosynthesis and ethylene response signaling pathways. COS02g_02406 may enable plants to cope with metal stress by regulating isoflavonoid biosynthesis involved in antioxidant defense and metal chelation. COS06g_03984 promotes the binding of Cd2+ to ETR/ERS, resulting in Cd absorption and tolerance. The results confirm the feasibility of high-throughput phenotyping for studying plant Cd tolerance by combining HSI and ML approaches, facilitating future molecular breeding.

Recent Advances in Dissecting the Function of Ethylene in Interaction between Host and Pathogen

Pathogens influence the growth and development of plants, resulting in detrimental damage to their yields and quality. Ethylene, a gaseous phytohormone, serves a pivotal function in modulating diverse physiological processes in plants, including defense mechanisms against pathogen invasion. Ethylene biosynthesis is involved in both plants and pathogens. Recent empirical research elucidates the intricate interactions and regulatory mechanisms between ethylene and pathogens across various plant species. In this review, we provide a comprehensive overview of the latest findings concerning ethylene's role and its regulatory networks in host-pathogen interactions. Additionally, we explore the crosstalk between ethylene and other phytohormones. Points regarding ethylene emission and its modulation by pathogens are also emphasized. Moreover, we also discuss potential unresolved issues in the field that warrant further investigation.

Genome-wide identification and comprehensive analysis of the phytochrome-interacting factor (PIF) gene family in wheat

Phytochrome-interacting factors (PIFs) are essential transcription factors for plant growth, development, and stress responses. Although PIF genes have been extensively studied in many plant species, they have not been thoroughly investigated in wheat. Here, we identified 18 PIF genes in cultivated hexaploid wheat (Triticum aestivum L). Phylogenetic analysis, exon-intron structures, and motif compositions revealed the presence of four distinct groups of TaPIFs. Genome-wide collinearity analysis of PIF genes revealed the evolutionary history of PIFs in wheat, Oryza sativa, and Brachypodium distachyon. Cis-regulatory element analysis suggested that TaPIF genes indicated participated in plant development and stress responses. Subcellular localization assays indicated that TaPIF2-1B and TaPIF4-5B were transcriptionally active. Both were found to be localized to the nucleus. Gene expression analyses demonstrated that TaPIFs were primarily expressed in the leaves and were induced by various biotic and abiotic stresses and phytohormone treatments. This study provides new insights into PIF-mediated stress responses and lays a strong foundation for future investigation of PIF genes in wheat.

Integrative Analysis of Metabolomic and Transcriptomic Data Reveals the Mechanism of Color Formation in Corms of Pinellia ternata

Pinellia ternata (Thunb.) Breit. (P. ternata) is a very important plant that is commonly used in traditional Chinese medicine. Its corms can be used as medicine and function to alleviate cough, headache, and phlegm. The epidermis of P. ternata corms is often light yellow to yellow in color; however, within the range of P. ternata found in JingZhou City in Hubei Province, China, there is a form of P. ternata in which the epidermis of the corm is red. We found that the total flavonoid content of red P. ternata corms is significantly higher than that of yellow P. ternata corms. The objective of this study was to understand the molecular mechanisms behind the difference in epidermal color between the two forms of P. ternata. The results showed that a high content of anthocyanidin was responsible for the red epidermal color in P. ternata, and 15 metabolites, including cyanidin-3-O-rutinoside-5-O-glucoside, cyanidin-3-O-glucoside, and cyanidin-3-O-rutinoside, were screened as potential color markers in P. ternata through metabolomic analysis. Based on an analysis of the transcriptome, seven genes, including PtCHS1, PtCHS2, PtCHI1, PtDFR5, PtANS, PtUPD-GT2, and PtUPD-GT3, were found to have important effects on the biosynthesis of anthocyanins in the P. ternata corm epidermis. Furthermore, two transcription factors (TFs), bHLH1 and bHLH2, may have regulatory functions in the biosynthesis of anthocyanins in red P. ternata corms. Using an integrative analysis of the metabolomic and transcriptomic data, we identified five genes, PtCHI, PtDFR2, PtUPD-GT1, PtUPD-GT2, and PtUPD-GT3, that may play important roles in the presence of the red epidermis color in P. ternata corms.

Jasmonic Acid as a Mediator in Plant Response to Necrotrophic Fungi

Jasmonic acid (JA) and its derivatives, all named jasmonates, are the simplest phytohormones which regulate multifarious plant physiological processes including development, growth and defense responses to various abiotic and biotic stress factors. Moreover, jasmonate plays an important mediator’s role during plant interactions with necrotrophic oomycetes and fungi. Over the last 20 years of research on physiology and genetics of plant JA-dependent responses to pathogens and herbivorous insects, beginning from the discovery of the JA co-receptor CORONATINE INSENSITIVE1 (COI1), research has speeded up in gathering new knowledge on the complexity of plant innate immunity signaling. It has been observed that biosynthesis and accumulation of jasmonates are induced specifically in plants resistant to necrotrophic fungi (and also hemibiotrophs) such as mostly investigated model ones, i.e., Botrytis cinerea, Alternaria brassicicola or Sclerotinia sclerotiorum. However, it has to be emphasized that the activation of JA-dependent responses takes place also during susceptible interactions of plants with necrotrophic fungi. Nevertheless, many steps of JA function and signaling in plant resistance and susceptibility to necrotrophs still remain obscure. The purpose of this review is to highlight and summarize the main findings on selected steps of JA biosynthesis, perception and regulation in the context of plant defense responses to necrotrophic fungal pathogens.