Biology subjects

Jordine, A.

Publications and source records attributed to Jordine, A..

3 recordsLinked to original sources

bioRxiv2026

Chilling Nights Do Not Cause Starch Over-Accumulation and Trigger a Shift in Carbon Partitioning via SPS Toward Sucrose in Arabidopsis - Differing from Acclimation to Permanent Cold

Plants acclimate to low temperatures by remodeling carbohydrate metabolism. Permanent cold at 4/5{whitebullet} C induces well-characterized cold acclimation in plants, including accumulation of starch and soluble sugars. In natural environments, however, annual plants in their vegetative phase more frequently experience chilling nights (0-6{whitebullet} C nights followed by days at least 12{whitebullet} C warmer), whose metabolic consequences remain poorly understood. We investigated Col-0 Arabidopsis thaliana exposed to one or seven chilling nights and quantified central carbohydrate metabolites, starch, photosynthetic parameters, and maximal activities of enzymes linking sucrose synthesis and cleavage. We integrated these time-series data into a biologically constrained augmented neural ordinary differential equation (ANODE) model to infer diurnal reaction-rate dynamics. Chilling nights induced strong accumulation of sucrose, glucose, and fructose, particularly after seven nights. Both measured sucrose phosphate synthase (SPS) capacity and ANODE-predicted SPS rates increased. In contrast to permanent cold acclimation, daytime starch over-accumulation was absent. Thus, lacking starch over-accumulation together with increased SPS rates, chilling nights invoke distinct carbohydrate-partitioning patterns towards sucrose, indicating a fundamentally different acclimation strategy compared to well described permanent cold.

plant biology↗

bioRxiv2025

Unraveling synergistic and antagonistic effects of simultaneous versus single hypoxia-salt conditions in an evolutionary adapted plant species

Plants frequently encounter simultaneous stressors, requiring complex adaptive responses across regulatory levels. Although morphological and metabolic effects of combined hypoxia-salt stress are known in halophytes, transcriptional impacts remain largely unexplored. This study uses RNA sequencing to analyze Salicornia europaea which is an intertidal salt-marsh plant naturally adapted to these conditions. Combined hypoxia-salt stress induced a distinct gene expression profile in which 16% of genes were exclusively changed. Synergistic, antagonistic, and additive effects were observed across all evaluated functional pathway categories. A data-driven analysis of carbohydrate metabolism, cellular respiration/fermentation, and amino acid pathways revealed that antagonistic effects were more prevalent than synergistic ones in both roots and shoots. Notably higher gene expression levels during hypoxia-salt of sucrose biosynthesis (consistent with salt), sucrose synthase (SUS) and trehalose-6-phosphate phosphatase (TPP, consistent with hypoxia) indicate enhanced sucrose and trehalose metabolism. The parallel down-regulation of invertase genes (consistent with hypoxia) suggests strategic carbon flux redistribution for optimized energy supply. Under hypoxic conditions, lactate dehydrogenase (LDH) expression was up-regulated, indicating active lactate fermentation rather than ethanol production via alcohol dehydrogenase (ADH). Enhanced proline synthesis under combined stress suggests improved osmoprotection. These insights into transcriptional reprogramming under single and combined hypoxia-salt conditions emphasize the intricate regulatory strategies plants utilize to manage concurrent stressors, showcasing their ability to adapt and develop stress resilience.

plant biology↗

bioRxiv2020

Wheat blast caused by Magnaporthe oryzae pv. Triticum is efficiently controlled by the plant defence inducer isotianil

Wheat blast caused by Magnaporthe oryzae pv. Triticum (MoT) is an upcoming threat to wheat cultivation worldwide. The disease crossing over to wheat first gained attention in South America, with increasing interest coming from its more recent appearance in the big wheat growing areas of Asia. The increasing economic relevance of the disease and the lack of genetic resistance in current wheat breading material, besides fungicide resistance already present in fungal pathogen populations, highlighted the need to evaluate the potential of isotianil as an alternative plant protection measure. Isotianil is already registered in Asia for the protection of rice against M. oryzae but because the agronomic practices and disease development of blast differ between rice and wheat, the efficacy of isotianil against wheat blast was hard to predict. Testing isotianil in the currently available formulations, applied either as seed treatment or soil drench, resulted in a significant reduction of disease severity. The efficacy was comparably high, on different wheat cultivars and using several fungal isolates with different degrees of virulence. Microscopic analyses revealed that isotianil treatment can prevent invasive growth of the pathogen. No phytotoxicity from isotianil treatment was observed on wheat plants up to the stage of heading. Importantly, isotianil not only protects wheat plants at the seedling stage but also on spikes thereby preventing losses due to this most severe disease syndrome. In summary, the results showed the high potential of isotianil to protect against wheat blast.

plant biology↗