Phosphite (Phi) and phosphate (Pi) share the same root uptake system, but Phi acts as a biostimulant that modulates plant growth and disease resistance in a species‑ and Pi‑dependent manner. In Arabidopsis, Phi induces hypersensitive‑like cell death and enhances resistance to Plectosphaerella cucumerina, while in rice it counteracts Pi‑induced susceptibility to Magnaporthe oryzae and Fusarium fujikuroi, accompanied by extensive transcriptional reprogramming.
The authors used a bottom‑up thermodynamic modelling framework to investigate how plants decode calcium signals, starting from Ca2+ binding to EF‑hand proteins and extending to higher‑order decoding modules. They identified six universal Ca2+-decoding modules that can explain variations in calcium sensitivity among kinases and provide a theoretical basis for interpreting calcium signal amplitude and frequency in plant cells.
Novel substrate affinity of FaCCR1 and FaCCR1/FaOCT4 expression control the content of medium-chain esters in strawberry fruit
Authors: Roldan-Guerra, F. J., Amorim-Silva, V., Jimenez, J., Mari-Albert, A., Torreblanca, R., Ruiz del Rio, J., Botella, M. A., Granell, A., Sanchez-Sevilla, J. F., Castillejo, C., Amaya, I.
The study identified a major QTL on chromosome 6A that accounts for 40% of variation in medium-chain ester (MCE) levels in strawberry fruit, pinpointing FaCCR1 and FaOCT4 as the causal genes. Functional validation through subcellular localization, transient overexpression, enzymatic assays, and molecular docking demonstrated that FaCCR1 also catalyzes MCE precursor reactions, and a KASP marker in FaOCT4 was developed for breeding fragrant cultivars.
The study genotyped 1,013 hard red spring wheat lines using SNP arrays and targeted KASP markers to track changes in genetic diversity and the distribution of dwarfing Rht alleles over a century of North American breeding. It found shifts from Rht‑D1b to Rht‑B1b dominance, identified low‑frequency dwarf alleles at Rht24 and Rht25 that have increased recently, and revealed gene interactions that can fine‑tune plant height, along with evidence of recent selection for photoperiod sensitivity.
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.
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.
Using hydathode-focused inoculation, the study mapped a major QTL on Arabidopsis chromosome 5 and identified the CNL-type immune receptor SUT1 as a novel resistance gene that restricts early colonization of Xanthomonas campestris pv. campestris in hydathodes. Functional analyses showed SUT1 acts independently of the known RKS1/ZAR1 complex and provides tissue‑specific resistance, being effective primarily in hydathodes but not in xylem.
A biparental Vicia faba mapping population was screened under glasshouse conditions for resistance to a mixture of Fusarium avenaceum and Fusarium oxysporum, revealing several families with moderate to high resistance. Using the Vfaba_v2 Axiom SNP array, a high-density linkage map of 6,755 SNPs was constructed, enabling the identification of a major QTL on linkage group 4 associated with partial resistance to foot and root rot.