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 compares iron deficiency and drought tolerance between two soybean genotypes, Clark (tolerant) and Arisoy (sensitive), using multi‑omics analyses. Clark maintains iron homeostasis, higher antioxidant protein expression, and recruits beneficial root microbes (Variovorax, Paecilomyces) that support nutrient uptake and nodule function, while Arisoy shows impaired physiological and microbial responses. The findings identify host‑microbe interactions and specific molecular pathways as potential targets for breeding and microbiome‑based biofertilizers.
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.
The study shows that drought triggers ABA accumulation and JA reduction in sorghum roots, accompanied by transcriptional activation of genes linked to mineral homeostasis, hormone signaling, and osmotic regulation, while Fe supplementation enhances ferritin expression and mitigates oxidative stress. Drought also diminishes root bacterial diversity but enriches beneficial taxa such as Burkholderia, whereas fungal diversity remains stable, and functional profiling reveals shifts toward phototrophy, methylotrophy, and nitrate reduction. These findings highlight ferritin’s protective role and suggest specific bacterial inoculants for improving sorghum drought resilience.