Unravelling the intraspecific variation in drought responses in seedlings of European black pine (Pinus nigra J.F. Arnold)
Authors: Ahmad, M., Hammerbacher, A., Priemer, C., Ciceu, A., Karolak, M., Mader, S., Olsson, S., Schinnerl, J., Seitner, S., Schoendorfer, S., Helfenbein, P., Jakub, J., Breuer, M., Espinosa, A., Caballero, T., Ganthaler, A., Mayr, S., Grosskinsky, D. K., Wienkoop, S., Schueler, S., Trujillo-Moya, C., van Loo, M.
The study examined drought tolerance across nine provenances of the conifer Pinus nigra using high‑throughput phenotyping combined with metabolomic and transcriptomic analyses under controlled soil‑drying conditions. Drought tolerance, measured by the decline in Fv/Fm, varied among provenances but was not linked to a climatic gradient and was independent of growth, with tolerant provenances showing distinct flavonoid and diterpene profiles and provenance‑specific gene expression patterns. Integrating phenotypic and molecular data revealed metabolic signatures underlying drought adaptation in this non‑model conifer.
The study compared physiological and transcriptomic responses of poplar trees colonized by the ectomycorrhizal fungi Paxillus involutus or Cenococcum geophilum under normal, drought, and recovery conditions. Cenococcum-colonized plants showed constitutive up‑regulation of heat‑shock proteins, galactinol synthase, and aquaporins and maintained water status and photosynthesis during severe drought, whereas Paxillus colonization promoted growth and nitrogen‑use efficiency and enabled rapid recovery through drought‑induced leaf shedding. These contrasting strategies illustrate species‑specific positions on the growth‑defense trade‑off in ectomycorrhizal symbiosis.
The study used host-mediated artificial selection to iteratively enrich rice-associated microbiomes that improve growth and drought tolerance, starting from diverse soil microbial communities. Over multiple generations, selected microbiomes converged, and amplicon sequencing along with metagenome-assembled genomes identified specific bacterial taxa and functional pathways (e.g., glycerol-3-phosphate and iron transport) linked to enhanced drought performance. The results demonstrate the effectiveness of plant phenotype-driven microbiome engineering for crop improvement.
Comparative gene regulatory network mapping of Brassicaceae members with differential drought tolerance
Authors: Pandiarajan, R., Lin, C.-W., Sauer, M., Rothballer, S. T., Marin-de la Rosa, N., Schwehn, P., Papadopoulou, E., Mairhormann, B., Falter-Braun, P.
The study mapped drought‑responsive gene regulatory networks in Arabidopsis thaliana, its tolerant relative Arabidopsis lyrata, and Eutrema salsugineum using yeast one‑hybrid screens of orthologous promoters, revealing higher network connectivity and specific TF‑promoter interactions in the tolerant species. Notable findings include an Esa‑specific expansion of bZIP interactions, differential ABA‑signalling edges, and the identification of ASIL2 as a novel stress‑responsive factor, providing a comparative framework for improving crop drought tolerance.
The study applied spatial transcriptomics to map the transcriptional landscape of wheat (Triticum aestivum) inflorescences during spikelet development, revealing two distinct regions—a RAMOSA2‑active primordium and an ALOG1‑expressing boundary. Developmental assays showed that spikelets arise from meristematic zones accompanied by vascular rachis formation, identifying key regulators that could be targeted to improve spikelet number and yield.
The study evaluated drought tolerance and yield stability of eleven Andean amaranth genotypes (A. caudatus and A. mantegazzianus) across four agroecological zones in Northwest Argentina under irrigated and drought‑stressed conditions. Using linear mixed models and AMMI analysis, significant genotype and genotype‑by‑environment effects were detected, identifying several breeding lines with high yield and stability as well as a highly stable but low‑yielding landrace. The results highlight both broad and specific adaptation among amaranth genotypes for drought‑prone environments.
An optimized workflow was developed to apply the Xenium in situ sequencing platform to formalin‑fixed paraffin‑embedded (FFPE) sections of Medicago truncatula roots and nodules, incorporating customized tissue preparation, probe design, and imaging to overcome plant‑specific challenges such as cell wall autofluorescence. The protocol was validated across nodule developmental stages using both a 50‑gene panel for mature cell identity and an expanded 480‑gene panel covering multiple cell types, providing a scalable high‑resolution spatial transcriptomics method adaptable to other plant systems.
The study used a yeast two-hybrid screen to identify 52 wheat proteins that interact with the inositol pyrophosphate kinase TaVIH2-3B, highlighting the fasciclin‑like arabinogalactan protein TaFLA7 as a key partner involved in cell‑wall functions. Pulldown assays and reporter fusion analyses confirmed the interaction and plasma‑membrane localization of TaFLA7, which is modulated by TaVIH2‑3B activity and shows drought‑responsive and grain‑development expression in wheat.
Double mutant hybrids in the miR394‑regulated genes ZmLCR1 and ZmLCR2, created in a W22/B73 maize background, display enhanced drought tolerance through increased epicuticular wax and reduced ROS production, while maintaining normal flowering and nutrition. Under field rainfed conditions the mutants achieve significantly higher yields (greater ear weight and kernel number) compared to wild‑type hybrids.
The study used RNA-Seq to examine transcriptional responses to dehydration in seedlings of the drought‑tolerant oak Quercus douglasii, comparing dry‑down and well‑watered treatments. Few genes were differentially expressed, but many drought‑responsive genes showed high constitutive expression, indicating that Q. douglasii relies on a combination of constitutive expression and limited plasticity to tolerate drought.