Biology subjects

Acosta, I. F.

Publications and source records attributed to Acosta, I. F..

5 recordsLinked to original sources

bioRxiv2024

Morphological and molecular effects of short-term water deficiency in barley stamen maturation

Water deficiency at the reproductive stage of cereal crops mainly affects the development or function of male organs, which causes strong losses in grain yield. We investigated the effects of short-term drought on the post-meiotic maturation of stamens in barley cultivar Scarlett, where it leads to a stage-dependent decline in fertility. Water deficiency neither affects pollen viability nor the formation of trinuclear pollen. However, it completely blocks pollen starch accumulation. Metabolite profiling suggests that this is due to decreased sugar content at starch-filling stages, probably reflecting impaired carbon supply from photosynthetic tissues to anther sinks. Accordingly, transcriptomic analysis shows that drought reduces the expression of stamen sugar transporters. Moreover, drought causes a strong downregulation of the pollen transcriptional network of auxin signalling and central carbon metabolism genes that controls barley pollen starch production. This wider model of the molecular effects of water deficiency on cereal pollen provides a solid foundation to characterize tolerance mechanisms in potential drought-resistant germplasm.

plant biology↗

bioRxiv2024

Aluminium induces suberin biosynthesis in barley roots via ABA

Aluminum (Al) toxicity is a major factor limiting plant growth in acidic soils. The beneficial element silicon (Si) can mitigate some effects of Al. However, the impact of Al on suberized apoplastic barriers in roots are largely unknown while the effects of Si on suberin remains controversial. This study employed physiological, histochemical, and analytical methods, along with Laser Capture Microdissection (LCM) RNA-sequencing, to explore the effects of Al and Si on suberin development in barley (Hordeum vulgare L.), a species sensitive to Al stress. Exposure of barley seedlings to Al resulted in increased suberin deposition, which could be restored with the addition of Si, particularly in the root endodermis. Gene expression analyses using LCM RNA-seq across different root tissues demonstrated that Al-induced suberin biosynthesis is mainly regulated by the abscisic acid (ABA) pathway. In addition, the application of fluridone, an inhibitor of ABA synthesis and a suberin mutant, further supported the pivotal role of ABA in the Al response and the role of suberin in influencing Al uptake. Our findings underscore the complex interplay between Al stress and suberin biosynthesis in barley, providing insights into potential strategies for enhancing crop resilience to Al toxicity.

plant biology↗

bioRxiv2024

CLAVATA signalling shapes barley inflorescence architecture by controlling activity and determinacy of shoot apical and rachilla meristems

Grasses exhibit a large variety of diverse inflorescence architectures, from complex branched inflorescences in Oryzeae (rice) to simple spike-type inflorescences in Triticeae (e.g. barley, wheat). Inflorescence architecture depends on shape, longevity and determinacy of meristems that direct growth of the main rachis and lateral branches, but how individual meristem activities are determined and integrated within complex inflorescences is not yet understood. We found that activity of distinct meristems in the barley inflorescence is coordinated by a signalling pathway comprising the receptor like kinase Hordeum vulgare CLAVATA1 (HvCLV1) and the secreted CLAVATA3/ENDOSPERM SURROUNDING REGION (CLE)-family peptide FON2- LIKE CLE PROTEIN1 (HvFCP1). HvFCP1 interacts with HvCLV1 to promote spikelet formation but restricts inflorescence meristem and rachilla meristem proliferation. Hvfcp1 or Hvclv1 mutants generate branched inflorescences with additional rows of spikelets and supernumerary florets. Transcriptome analysis reveals that HvFCP1/HvCLV1 signalling controls inflorescence branching through the regulation of trehalose-6-phosphate synthesis and sugar transport. Our discoveries reveal the potential to engineer barley inflorescence architecture by manipulating regulation of distinct meristem activities.

plant biology↗

bioRxiv2023

Metabolic arms race between a plant and a fungal pathogen

In this work, we uncover a metabolite interaction between barley and the fungal pathogen Bipolaris sorokiniana (Bs), involving hordedanes, a previously undescribed set of labdane-related diterpenoids with antimicrobial properties. Bs infection of barley roots elicits hordedane synthesis from a 600-kb gene cluster. Heterologous reconstruction of the synthesis pathway in yeast produced several hordedanes, including one of the most advanced products 19-b-hydroxy-hordetrienoic acid (19-OH-HTA). Barley mutants in the diterpene synthase genes of the cluster are unable to produce hordedanes but, unexpectedly, show reduced Bs colonization. Accordingly, 19-OH-HTA enhances both germination and growth of Bs, while it inhibits other fungi, and Bs chemically modifies 19-OH-HTA. Thus, plant and pathogen molecular interactions extend beyond protein-protein recognition and the simple detoxification of plant antimicrobial metabolites. One-Sentence SummaryA fungal pathogen uses barley diterpenoid phytoalexins to facilitate root colonization.

plant biology↗

bioRxiv2023

A GH81-type β-glucan-binding protein facilitates colonization by mutualistic fungi in barley

Cell walls are important interfaces of plant-fungal interactions. Host cell walls act as robust physical and chemical barriers against fungal invaders, making them an essential line of defense. Upon fungal colonization, plants deposit phenolics and callose at the sites of fungal penetration to reinforce their walls and prevent further fungal progression. Alterations in the composition of plant cell walls significantly impact host susceptibility. Furthermore, plants and fungi secrete glycan hydrolases acting on each others cell walls. These enzymes release a wide range of sugar oligomers into the apoplast, some of which trigger the activation of host immunity via host surface receptors. Recent characterization of cell walls from plant-colonizing fungi have emphasized the abundance of {beta}-glucans in different cell wall layers, which makes them suitable targets for recognition. To characterize host components involved in immunity against fungi, we performed a protein pull-down with the biotinylated {beta}-glucan laminarin. Thereby, we identified a glycoside hydrolase family 81-type glucan-binding protein (GBP) as the major {beta}-glucan interactor. Mutation of GBP1 and its only paralogue GBP2 in barley led to decreased colonization by the beneficial root endophytes Serendipita indica and S. vermifera, as well as the arbuscular mycorrhizal fungus Rhizophagus irregularis. The reduction of symbiotic colonization was accompanied by enhanced responses at the host cell wall. Moreover, GBP mutation in barley also increased resistance to fungal infections in roots and leaves by the hemibiotrophic pathogen Bipolaris sorokiniana and the obligate biotrophic pathogen Blumeria graminis f. sp. hordei, respectively. These results indicate that GBP1 is involved in the establishment of symbiotic associations with beneficial fungi, a role that has potentially been appropriated by barley-adapted pathogens. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=134 SRC="FIGDIR/small/536646v1_figu1.gif" ALT="Figure 1"> View larger version (39K): org.highwire.dtl.DTLVardef@c47957org.highwire.dtl.DTLVardef@fa6727org.highwire.dtl.DTLVardef@18a54d2org.highwire.dtl.DTLVardef@c6b103_HPS_FORMAT_FIGEXP M_FIG C_FIG In BriefGBP1, a family 81 glycoside hydrolase, is an important {beta}-glucan interactor in barley. Mutation of GBP1 and its sole paralogue GBP2 leads to reduced colonization by beneficial root endophytes, AM fungi and pathogens, accompanied by enhanced responses at the plant cell wall. This indicates that GBP1 and {beta}-glucans are compatibility factors involved in the establishment of symbiotic associations with beneficial fungi, a role possibly hijacked by pathogens.

plant biology↗