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 identified seven adult plant resistance QTL for oat crown rust using two recombinant inbred line populations, with a major QTL (QPc_GS7_4A.2) on chromosome 4A closely linked to the Pc61 resistance gene. KASP markers targeting SNPs tightly linked to the four most significant QTL were developed, and genetic and haplotype analyses confirmed the association of QPc_GS7_4A.2 with both seedling and adult plant resistance, providing valuable tools for oat breeding.
The study investigates the evolutionary shift from archegonial to embryo‑sac reproduction by analyzing transcriptomes of Ginkgo reproductive organs and related species. It reveals that the angiosperm pollen‑tube guidance module MYB98‑CRP‑ECS is active in mature Ginkgo archegonia and that, while egg cell transcription is conserved, changes in the fate of other female gametophyte cells drove the transition, providing a molecular framework for this major reproductive evolution.
The study investigates the genetic basis of sex determination in Cannabis sativa, identifying a X‑chromosome locus (Monoecy1) that governs the switch between dioecy and monoecy. Transcriptomic and genomic analyses reveal three tightly linked genes with sex‑specific expression, suggesting their combined action controls both flower type and individual sex phenotype.
The study profiled root transcriptomes of Arabidopsis wild type and etr1 gain-of-function (etr1-3) and loss-of-function (etr1-7) mutants under ethylene or ACC treatment, identifying 4,522 ethylene‑responsive transcripts, including 553 that depend on ETR1 activity. ETR1‑dependent genes encompassed ethylene biosynthesis enzymes (ACO2, ACO3) and transcription factors, whose expression was further examined in an ein3eil1 background, revealing that both ETR1 and EIN3/EIL1 pathways regulate parts of the network controlling root hair proliferation and lateral root formation.
The study validates and quantifies biological nitrogen fixation in Mexican maize varieties and assesses a double‑haploid population derived from an elite inbred (PHZ51) crossed with these landraces. Aerial root traits show moderate to high heritability, and QTL mapping reveals multiple loci influencing root number, node occurrence, and diameter, with most favorable alleles originating from the landraces. The authors suggest that pyramiding the identified QTL into elite germplasm could enhance maize’s BNF capacity, pending field validation.
The study used QTL mapping in two F1 Plasmopara viticola populations to locate avirulence genes linked to grapevine resistance loci Rpv3.1, Rpv10, and Rpv12, confirming AvrRpv3.1 and identifying AvrRpv12, which harbors large deletions of RXLR effector genes. Additionally, a dominant locus responsible for partial Rpv10 breakdown was discovered, revealing diverse evolutionary mechanisms—including structural rearrangements and admixture—that enable the pathogen to overcome host resistance.
A comparative physiological study of persimmon cultivars with flat (Hiratanenashi) and round (Koushimaru) fruit shapes revealed that differences in cell proliferation, cell shape, and size contribute to shape variation. Principal component analysis of elliptic Fourier descriptors tracked shape changes, while histology and transcriptome profiling identified candidate genes, including a WOX13 homeobox gene, potentially governing fruit shape development.
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.
The study investigated how Arabidopsis thaliana SR protein kinases (AtSRPKs) regulate alternative RNA splicing by using chemical inhibitors of SRPK activity. Inhibition with SPHINX31 and SRPIN340 caused reduced root growth and loss of root hairs, accompanied by widespread changes in splicing and phosphorylation of genes linked to root development and other cellular processes. Multi‑omics analysis (transcriptomics and phosphoproteomics) revealed that AtSRPKs modulate diverse splicing factors and affect the splicing landscape of numerous pathways.