Integrative comparative transcriptomics using cultivated and wild rice reveals key regulators of developmental and photosynthetic progression along the rice leaf developmental gradient
Authors: Jathar, V., Vivek, A., Panda, M. K., Daware, A. V., Dwivedi, A., Rani, R., Kumar, S., Ranjan, A.
The study performed comparative gene expression profiling across four rice accessions—from shoot apical meristem to primordia stage P5—to delineate developmental and photosynthetic transitions in leaf development. By integrating differential expression and gene regulatory network analyses, the authors identified stage-specific regulatory events and key transcription factors, such as RDD1, ARID2, and ERF3, especially in the wild rice Oryza australiensis, offering a comprehensive framework for optimizing leaf function.
The study engineers Type‑B response regulators to alter their transcriptional activity and cytokinin sensitivity, enabling precise modulation of cytokinin‑dependent traits. Using tissue‑specific promoters, the synthetic transcription factors were deployed in Arabidopsis thaliana to reliably increase or decrease lateral root numbers, demonstrating a modular platform for controlling developmental phenotypes.
Advanced illumination-imaging reveals photosynthesis-triggered pH, ATP and NAD redox signatures across plant cell compartments
Authors: Zheng, K., Elsässer, M., Niemeier, J.-O., Barreto, P., Cislaghi, A. P., Hoang, M., Feitosa-Araujo, E., Wagner, S., Giese, J., Kotnik, F., Martinez, M. d. P., Buchert, F. E., Ugalde, J. M., Armbruster, U., Hippler, M., Meyer, A. J., Kunz, H.-H., Maurino, V. G., Finkemeier, I., Schallenberg-Rüdinger, M., Schwarzländer, M.
The authors established a live‑cell imaging platform that combines confocal microscopy of genetically encoded fluorescent protein biosensors with on‑stage illumination to monitor pH, MgATP²⁻, and NADH/NAD⁺ dynamics during dark‑light transitions in Arabidopsis mesophyll cells. They discovered that photosynthetic proton pumping triggers a stromal alkalinization wave extending to the cytosol and mitochondria, elevates MgATP²⁻ levels, and drives reduction of the NAD pool, with malate dehydrogenase mutants showing altered cytosolic redox even in darkness. This methodological advance enables high‑resolution mapping of photosynthesis‑linked energy physiology across cellular compartments.
The study compared photosynthetic performance and carbon metabolism in mature versus immature leaves of Arabidopsis thaliana accessions from different latitudes under standard and low‑temperature/high‑light conditions. Leaf‑specific measurements of Fv/Fm and CO2 assimilation revealed distinct acclimation capacities, and integration of carbohydrate and carboxylic‑acid profiles into a carbon balance model indicated that mature leaves help stabilize metabolism in younger tissue. The authors emphasize the importance of accounting for intra‑rosette heterogeneity to avoid misleading metabolic interpretations.
The study examines how the SnRK1 catalytic subunit KIN10 integrates carbon availability with root growth regulation in Arabidopsis thaliana. Loss of KIN10 reduces glucose‑induced inhibition of root elongation and triggers widespread transcriptional reprogramming of metabolic and hormonal pathways, notably affecting auxin and jasmonate signaling under sucrose supplementation. These findings highlight KIN10 as a central hub linking energy status to developmental and environmental cues in roots.
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.