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 generated a phenotypic dataset for 550 Lactuca accessions, including 20 wild relatives, and applied an iterative two‑step GWAS using a jointly processed SNP set for cultivated lettuce (L. sativa) and its wild progenitor (L. serriola) to dissect trait loci. Known and novel QTLs for anthocyanin accumulation, leaf morphology, and pathogen resistance were identified, with several L. serriola‑specific QTLs revealing unique genetic architectures, underscoring the breeding value of wild lettuce species.
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 examined how tricarboxylic acid (TCA) cycle metabolites influence drought tolerance in grapevine and Arabidopsis, finding that malate uniquely triggers stomatal closure via elevations in cytosolic Ca2+ and activation of the SLAC1 anion channel. G-proteins were shown to be essential for malate‑mediated signaling, linking metabolic changes to drought response through a second‑messenger cascade.