Thermotolerant pollen tube growth is controlled by RALF signaling.
Authors: Althiab Almasaud, R., Ouonkap Yimga, S. V., Ingram, J., Oseguera, Y., Alkassem Alosman, M., Travis, C., Henry, A., Medina, M., Oulhen, N., Wessel, G. M., Delong, A., Pease, J., DaSilva, N., Johnson, M.
The study investigates the molecular basis of heat‑tolerant pollen tube growth in tomato (Solanum lycopersicum) by comparing thermotolerant and sensitive cultivars. Using live imaging, transcriptomics, proteomics, and genetics, the authors identified the Rapid Alkalinization Factor (RALF) signaling pathway as a key regulator of pollen tube integrity under high temperature, with loss of a specific RALF peptide enhancing tube integrity in a thermotolerant cultivar.
Daily Heat Stress Induces Accumulation of Non-functional PSII-LHCII and Donor-side Limitation of PSI via Downregulation of the Cyt bf Complex in Arabidopsis thaliana
The study examined the impact of daily moderate heat stress (38 °C for 4 h) on Arabidopsis thaliana, revealing altered thylakoid ultrastructure and structurally intact but functionally impaired PSII‑LHCII complexes. A pronounced reduction in cytochrome b6f content limited PSI on the donor side, suggesting that Cyt b6f down‑regulation serves as an acclimation mechanism that protects PSI at the expense of overall photosynthetic efficiency.
The study investigated metabolic responses of kale (Brassica oleracea) grown under simulated microgravity using a 2-D clinostat versus normal gravity conditions. LC‑MS data were analyzed with multivariate tools such as PCA and volcano plots to identify gravity‑related metabolic adaptations and potential molecular markers for spaceflight crop health.
The study investigated how native soil microbes affect heat tolerance in soybean (Glycine max) by comparing plants grown in natural versus microbiome‑disturbed soils under optimal and elevated temperatures. Using 16S rRNA and ITS sequencing alongside non‑targeted root metabolomics, the authors found significant shifts in bacterial and fungal communities, suppressed nodule‑forming bacteria, and altered root metabolites that correlated with reduced nodulation efficiency under heat stress. Integrated multi‑omics analyses linked microbial composition to metabolite profiles and nitrogen‑fixation traits, highlighting a coordinated response of the root physiological system to combined heat and microbiome perturbations.
The study used chlorophyll fluorescence imaging to map non-photochemical quenching (NPQ) gradients along barley leaf axes and found heat stress attenuates NPQ induction, revealing spatial heterogeneity in stress responses. Genome‑wide association and transcriptomic analyses identified candidate genes, notably HORVU.MOREX.r3.3HG0262630, that mediate region‑specific heat responses, highlighting pathways for improving cereal heat resilience.
Multi-Omics Analysis of Heat Stress-Induced Memory in Arabidopsis
Authors: Thirumlaikumar, V. P. P., Yu, L., Arora, D., Mubeen, U., Wisniewski, A., Walther, D., Giavalisco, P., Alseekh, S., DL Nelson, A., Skirycz, A., Balazadeh, S.
The study uses a high‑throughput comparative multi‑omics strategy to profile transcript, metabolite, and protein dynamics in Arabidopsis thaliana seedlings throughout the heat‑stress memory (HSM) phase following acquired thermotolerance. Early recovery stages show rapid transcriptional activation of memory‑related genes, while protein levels stay elevated longer, and distinct metabolite patterns emerge, highlighting temporal layers of the memory process.
The study tracked molecular changes in plastoglobules and thylakoids of Zea mays B73 during heat stress and recovery, revealing increased plastoglobule size, number, and adjacent lipid droplets over time. Proteomic and lipidomic analyses uncovered up‑regulation of specific plastoglobule proteins and alterations in triacylglycerol, plastoquinone derivatives, and phytol esters, suggesting roles in membrane remodeling and oxidative defense. These insights highlight plastoglobule‑associated pathways as potential targets for enhancing heat resilience in maize.
The study compared two plasma‑activated water (PAW) solutions with different H₂O₂ levels, produced by a radio‑frequency glow discharge, on Arabidopsis thaliana growth and stress responses. PAW lacking detectable H₂O₂ promoted seedling growth and induced nitrogen‑assimilation genes, while H₂O₂‑containing PAW did not affect growth but enhanced root performance under heat stress; mature plants fertilized with H₂O₂‑free PAW performed comparably to nitrate controls. These results indicate PAW can replace NO₃⁻ fertilizers provided H₂O₂ levels are carefully managed.
The study used transcriptomic and lipidomic profiling to investigate how chia (Salvia hispanica) leaves respond to short‑term (3 h) and prolonged (27 h) heat stress at 38 °C, revealing rapid activation of calcium‑signaling and heat‑shock pathways and reversible changes in triacylglycerol levels. Nearly all heat‑responsive genes returned to baseline expression after 24 h recovery, highlighting robust thermotolerance mechanisms that could inform improvement of other oilseed crops.
Transcriptomic profiling of desert tree Prosopis cineraria under heat stress reveals potential role of multiple gene families in its high thermotolerance
Prosopis cineraria plants were exposed to two heat stress regimes (45 °C and 55 °C) and subjected to transcriptome sequencing, revealing 1,151 and 1,562 differentially expressed genes respectively, with the higher temperature eliciting a stronger response. Bioinformatic analysis highlighted multiple gene families associated with thermotolerance, and the expression of selected heat‑responsive genes was confirmed by real‑time qPCR, providing candidate loci for crop improvement.