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.
Energy trade-offs under fluctuating light govern bioenergetics and growth in Chlamydomonas reinhardtii
Authors: Pfleger, A., Arc, E., Zhang, S., Chaturvedi, P., Antoine, E., Gnaiger, E., Ghatak, A., Afjehi-Sadat, L., Weckwerth, W., Kranner, I., Roach, T.
The study examined how Chlamydomonas reinhardtii adjusts its metabolism under fluctuating light (FL) compared with constant high or low light, across high and low CO2 conditions. Proteomic and metabolomic analyses revealed that low CO2 drives a carbon‑concentrating mechanism and photorespiration, while high CO2 supports growth by increasing ATP pools and promoting mitochondrial respiration, cyclic electron flow, and starch turnover. The results highlight a CO2‑dependent energy trade‑off between photoprotection, repair, and carbon allocation that governs growth under FL.
The study demonstrates that in the green alga Chlamydomonas reinhardtii, distinct photosynthetic electron flow pathways each operate efficiently over specific light‑fluctuation frequencies, defined as their bandwidths. By systematically varying light periodicities, the authors show that cyclic electron flow handles a broad range, pseudo‑cyclic electron flow supports rapid fluctuations, and chloroplast‑mitochondria electron flow is limited to slower changes, linking these capacities to ATP generation and photoprotection. The findings suggest that cells dynamically adjust the contribution of each pathway according to the frequency of environmental light changes.
Arabidopsis lines with modified ascorbate concentrations reveal a link between ascorbate and auxin biosynthesis
Authors: Fenech, M., Zulian, V., Moya-Cuevas, J., Arnaud, D., Morilla, I., Smirnoff, N., Botella, M. A., Stepanova, A. N., Alonso, J. M., Martin-Pizarro, C., Amorim-Silva, V.
The study used Arabidopsis thaliana mutants with low (vtc2, vtc4) and high (vtc2/OE-VTC2) ascorbate levels to examine how ascorbate concentration affects gene expression and cellular homeostasis. Transcriptomic analysis revealed that altered ascorbate levels modulate defense and stress pathways, and that TAA1/TAR2‑mediated auxin biosynthesis is required for coping with elevated ascorbate in a light‑dependent manner.
PSII photoinhibition as a protective strategy against PSI photoinhibition: Maintaining PSI in an oxidized state by suppressing PSII activity under environmental stress
Authors: Takeuchi, K., Harimoto, S., Maekawa, S., Miyake, C., Ifuku, K.
The study demonstrates that photoinhibition of Photosystem II (PSII) serves as a protective mechanism against Photosystem I (PSI) photoinhibition under chilling stress and fluctuating light, using Arabidopsis thaliana and cucumber. Reduced PSII activity (lower Fv/Fm) kept PSI oxidized and limited ROS production by enhancing re‑oxidation of Fe‑S clusters, confirming PSII‑mediated protection in wild‑type plants.
Comparative multi-omics profiling of Gossypium hirsutum and Gossypium barbadense fibers at high temporal resolution reveals key differences in polysaccharide composition and associated glycosyltransferases
Authors: Swaminathan, S., Lee, Y., Grover, C. E., DeTemple, M. F., Mugisha, A. S., Sichterman, L. E., Yang, P., Xie, J., Wendel, J. F., Szymanski, D. B., Zabotina, O. A.
The study performed daily large-scale glycome, transcriptome, and proteome profiling of developing fibers from the two cultivated cotton species, Gossypium barbadense and G. hirsutum, across primary and secondary cell wall stages. It identified delayed cellulose accumulation and distinct compositions of xyloglucans, homogalacturonans, rhamnogalacturonan‑I, and heteroxylans in G. barbadense, along with higher expression of specific glycosyltransferases and expansins, suggesting these molecular differences underlie the superior fiber length and strength of G. barbadense.
The study evaluated how acute heat stress affects early-stage rice seedlings, identifying a critical temperature threshold that impairs growth. Transcriptomic profiling of shoots and roots revealed ethylene‑responsive factors (ERFs) as central regulators, with ethylene and jasmonic acid acting upstream, and pre‑treatment with these hormones mitigated heat damage. These findings highlight ERF‑hormone interaction networks as targets for improving rice heat resilience.
The study characterizes the tomato class B heat shock factor SlHSFB3a, revealing its age‑dependent expression in roots and its role in enhancing lateral root density by modulating auxin homeostasis. Overexpression of SlHSFB3a increases lateral root emergence, while CRISPR‑mediated knockouts produce the opposite phenotype, indicating that SlHSFB3a regulates auxin signaling through repression of auxin repressors and activation of the ARF7/LOB20 pathway.
The study investigates how fluctuating light and suboptimal temperature affect the coordination between electron transport and CO₂ assimilation in maize (Zea mays). At room temperature, fluctuating light causes a decoupling of these processes, which is mitigated by large pools of C₄ metabolites, whereas low temperatures restore tighter coupling through feedback downregulation of electron transport and increased light saturation of CO₂ assimilation.
Using the Euphorbia peplus genome, the authors performed organ‑specific transcriptomic profiling of the cyathium and combined it with gene phylogenies and dN/dS analysis to investigate floral‑development gene families. They found distinct SEP1 paralog expression, lack of E‑class gene duplications typical of other pseudanthia, and divergent expression patterns for CRC, UFO, LFY, AP3, and PI, suggesting unique developmental pathways in Euphorbia.