Biology subjects

Manrique, S.

Publications and source records attributed to Manrique, S..

4 recordsLinked to original sources

bioRxiv2025

Characterization of a dominant SmNac-like gene as a candidate for photosensitivity in the fruit peel of eggplant

Anthocyanins in the fruit peel of photosensitive eggplants exhibit a different distribution pattern compared to the photo-insensitive ones. The latter exhibits a uniform anthocyanin content, whereas photosensitive eggplants lack anthocyanin accumulation in areas not exposed to light, such as under the calyx, or have lower concentrations in less-exposed areas. In the current research work, genetic analysis of F1 and F2 populations revealed that the photo-insensitive phenotype in eggplants follows an autosomal dominant inheritance with a 3:1 ratio, indicating that the photosensitive trait is regulated by a single dominant gene. To locate and narrow down the genomic region underlying photosensitivity, a segregating F2 population was used for bulked segregant analysis sequencing (BSA-seq) and compared with previous QTLs identified in previous developed eggplants populations (ILs and MAGIC population). The accumulation of QTLs at the end of chromosome 10 postulate that chromose region as a hot spot for anthocyanin related traits. In our population all the QTLs considered overlap between the genomic region 84,1-87,9 Mb. Moreover, no DNA mutations in the progenitors of the eggplant accessions used were found. A RNA-seq analysis of bagged photosensitive and photo- insensitive eggplants was performed, as a result we identified the SmNAC1-like protein gene as a promising gene to be involved in fruit photosensitivity trait. In the photo-insensitive accession (IVIA- 371) SmNAC1-like protein was depply repressed compare to the photosensitive accession (ASI-S-1). No consistent mutations in the coding sequences (CDS) of SmNac-like protein locus among all the different eggplants accessions used were found, suggesting that other layer of regulation maybe acting in our eggplant accessions. These findings provide new insight into the regulation of the molecular mechanisms of anthocyanin biosynthesis in eggplant as point out for the first time the possible role of NAC transcription factors in the anthocyanin biosynthesis in eggplant.

plant biology↗

bioRxiv2025

SPOROCYTELESS/NOZZLE acts together with MADS-domain transcription factors to regulate an auxin-dependent network controlling the Megaspore Mother Cell development

The formation of the female gamete is a complex developmental process that begins with the differentiation of the Megaspore Mother Cell (MMC) within the ovule. SPOROCYTELESS/NOZZLE (SPL/NZZ) is the principal regulator of the MMC formation, as mutations in the SPL/NZZ gene lead to the failure of the MMC differentiation. Nonetheless, the SPL/NZZ-dependent regulatory pathway governing the MMC development remains largely unknown. Using a multi-omics approach, we identify direct SPL/NZZ targets and their downstream network. We discovered that SPL/NZZ interacts with ovule-identity MADS-domain transcription factor complexes, to regulate the expression of common target genes. By integrating the omics data with the analysis of either complementation or mutant lines, we describe a comprehensive regulatory mechanism, in which SPL/NZZ determines the differentiation of the MMC by acting on an auxin-dependent downstream network.

plant biology↗

bioRxiv2023

The irregular fruit green netting: An eggplant domestication trait controlled by the SmGLK2 gene with implications in fruit colour diversification

The distribution of chlorophylls in the eggplant (Solanum melongena) fruit peel can be uniform or display an irregular green netting pattern. The fruit green netting phenotype, manifested as a gradient of dark green netting, more intense in the proximal part of the fruit on a pale green background, is commonly present in eggplant wild relatives as well as in some eggplant landraces. During domestication and modern breeding of eggplant, uniform fruit colour has been selected. However, the fruit green netting contributes to a greater diversity of fruit colours. Here, we have used over 2,300 individuals from several germplasm and experimental populations, including a multi-parental MAGIC population for candidate genomic region identification, an F2 population for BSA-Seq, and advanced backcrosses for edges-to-core fine mapping, to determine that SmGLK2 is the gene underlying the irregular netting in eggplant fruits. We have also analysed the gene sequence of 178 S. melongena accessions and 22 wild relative species for tracing the evolutionary changes that the gene has undergone over the course of domestication. Three different mutations were identified leading to the absence of netting. The main causative indel results in the appearance of a premature stop codon disrupting the protein conformation and function, which was confirmed by Western blotting analysis and confocal microscopy observations. SmGLK2 has a major role in the regulation of chlorophyll biosynthesis in eggplant fruit peel, and therefore in eggplant fruit photosynthesis.

genetics↗

bioRxiv2023

HISTONE DEACETYLASE 19 REGULATES SHOOT MERISTEMLESS EXPRESSION IN THE CARPEL MARGIN MERISTEM CONTRIBUTING TO OVULE NUMBER DETERMINATION AND TRANSMITTING TRACT DIFFERENTIATION

The gynoecium is critical for the reproduction of flowering species as it contains the ovules and the tissues required for pollen germination and guidance. These tissues are collectively known as the reproductive tract (ReT) and comprise stigma, style and transmitting tract (TT). The ovules and the ReT originate from a meristem within the pistil named carpel margin meristem (CMM). SHOOT MERISTEMLESS (STM) is a key transcription factor required for meristem formation and maintenance. In all above-ground meristems, including the CMM, STM has to be locally downregulated to allow proper organ differentiation. However, how this downregulation is achieved in the CMM is unknown. In this work, we have studied HISTONE DEACETYLASE 19 (HDA19) role in ovule and ReT differentiation, based on the observation that hda19-3 mutant displays reduced ovule number and fails to properly differentiate the TT. Fluorescence activated cell sorting (FACS) coupled with RNA-seq revealed that in the CMM of hda19-3 mutant, genes promoting organ development are downregulated while meristematic markers, including STM, are upregulated. We found that HDA19 is fundamental to downregulate STM in the CMM, allowing ovule formation and TT differentiation. STM is ectopically expressed in hda19-3 at intermediate stages of pistil development, and its downregulation by RNA interference alleviated hda19-3 phenotypic defects. Furthermore, chromatin immunoprecipitation assays indicated that STM is a direct target of HDA19 during pistil development and that SEEDSTICK (STK) is required for the histone acetylation-mediated regulation of STM. Our results have led to the identification of the factors required for STM silencing in the gynoecium allowing organogenesis and tissue differentiation from the CMM.

plant biology↗