Biology subjects

Villanueva, G.

Publications and source records attributed to Villanueva, G..

4 recordsLinked to original sources

bioRxiv2026

Genetic dissection of a Solanum elaeagnifolium tertiary genepool introgression associated with 4-O-caffeoylquinic acid accumulation in eggplant

Caffeoylquinic acids (CQAs) are the major phenolic compounds in eggplant (Solanum melongena) fruit, with 5-O-caffeoylquinic acid (5-CQA; chlorogenic acid) as the predominant isomer, while crop wild relatives may offer novel variation for diversifying these profiles. Previous work detected a distinct phenolic acid profile in S. elaeagnifolium, a tertiary genepool wild relative of eggplant, and in advanced backcross materials carrying introgressions from this species. This profile was characterized by a secondary chromatographic peak eluting after 5-CQA, but the identity of this compound and the associated chromosome 1 region remained unresolved. Here, we combined HPLC-MS-based metabolite identification, fine mapping, and comparative microsynteny analysis to characterize this phenotype. The secondary peak was identified as 4-O-caffeoylquinic acid (4-CQA). Fine mapping across three consecutive selfing generations, involving 612 screened individuals and 21 informative recombinants, reduced the associated interval from 2.753 Mb to 0.211 Mb, delimiting a region containing 30 annotated genes. The 4-CQA peak was detected in both homozygous and heterozygous introgression-derived materials, consistent with dominant control of the trait. Structural comparison of the fine-mapped interval revealed broad conservation between S. melongena and S. elaeagnifolium, but also identified a localized structurally divergent block potentially underlying the secondary 4-CQA peak. Within this block, the S. elaeagnifolium interval harbors acetylajmalan esterase-like/GDSL-type genes and a transcript-supported putative novel donor-specific gene. Overall, this study highlights S. elaeagnifolium introgressions as a promising source of phenolic diversification and providing markers to facilitate the development of eggplant lines with a more diverse CQA profile and potentially enhanced functional quality.

plant biology↗

bioRxiv2024

Validation and identification of new QTLs for plant and fruit developmental and composition traits in eggplant under low N conditions

Enhancing plant adaptation to low input conditions is a fundamental goal for implementing sustainable agriculture. In the present study, two eggplant (Solanum melongena) accessions (MEL1 and MEL5), two introgression lines (ILs) derived from eggplant wild relatives S. dasyphyllum (IL-M1-D1) and S. insanum (IL-M5-I9), and a heterozygous version of this last IL (ILHet-M5-I9), along with hybrids among them were evaluated under low N (LN) conditions. IL-M1-D1 carries an introgressed fragment of 4.9 Mb in homozygosis from S. dasyphyllum on chromosome 2, while IL-M5-I9 and ILHet-M5-I9 carry an introgression of 21.5 Mb on chromosome 9 in homozygosis and heterozygosis, respectively, from S. insanum. Multiple quantitative trait loci (QTLs) for several traits of interest were associated with both introgressions under LN conditions in a previous study with segregating advanced backcrosses. Here we evaluated the performance of these materials for 22 agronomic and developmental traits under low N fertilization (LN) conditions. Hybrids with the ILs enabled the study of genetic background effects on QTLs expression. The materials evaluated showed a significant phenotypic variation, particularly within hybrids segregating for the introgression from S. insanum in chromosome 9. Statistical analysis revealed no significant differences among hybrids carrying or not the introgression on chromosome 2 of S. dasyphyllum, and only slight differences were observed between the IL-M1-D1 and its recurrent parent S. melongena MEL1, suggesting a limited impact of this introgression on chromosome 2 on the phenotype variation. However, the differences observed between IL-M5-I9 and its recurrent parent S. melongena MEL5, together with the association between genotypic and phenotypic variation in hybrids segregating for this introgression, allowed the identification of 13 QTLs on chromosome 9. These results successfully validated the previously identified QTLs for flavonol content in leaves, nitrogen balanced index, fruit mean weight, and nitrogen content in leaves and, also revealed nine new QTLs associated with the introgressed genomic region in chromosome 9. This study emphasizes the influence of environmental conditions, genotypes, and genetic backgrounds on the phenotypic expression of eggplant QTLs introgressed from wild relatives and highlights the importance of QTL validation. These findings contribute valuable insights for developing new eggplant cultivars for a more sustainable agriculture, particularly with adaptation to LN conditions.

plant biology↗

bioRxiv2024

Convergent evolution of plant prickles is drivenby repeated gene co-option over deep time

An enduring question in evolutionary biology concerns the degree to which episodes of convergent trait evolution depend on the same genetic programs, particularly over long timescales. Here we genetically dissected repeated origins and losses of prickles, sharp epidermal projections, that convergently evolved in numerous plant lineages. Mutations in a cytokinin hormone biosynthetic gene caused at least 16 independent losses of prickles in eggplants and wild relatives in the genus Solanum. Strikingly, homologs promote prickle formation across angiosperms that collectively diverged over 150 million years ago. By developing new Solanum genetic systems, we leveraged this discovery to eliminate prickles in a wild species and an indigenously foraged berry. Our findings implicate a shared hormone-activation genetic program underlying evolutionarily widespread and recurrent instances of plant morphological innovation.

evolutionary biology↗

bioRxiv2023

Evaluation of three sets of advanced backcrosses of eggplant with wild relatives from different genepools under low N fertilization conditions

The development of new cultivars with improved nitrogen use efficiency (NUE) is key for implementing sustainable agriculture practices. Crop wild relatives (CWRs) provide valuable genetic resources for breeding programs aimed at achieving this goal. In this study, three eggplant (Solanum melongena) accessions together with their advanced backcrosses (ABs; BC3 to BC5 generations) with introgressions from the wild relatives S. insanum, S. dasyphyllum, and S. elaeagnifolium were evaluated for 22 morpho-agronomic, physiological, and N use efficiency (NUE) traits under low nitrogen fertilization conditions. The three S. melongena recurrent parents were also evaluated under control (normal) N fertilization. Reduction of N fertilization in the parents resulted in decreased chlorophyll content-related traits, aerial biomass, stem diameter and yield, and increased NUE, nitrogen uptake efficiency (NUpE), and nitrogen utilization efficiency (NUtE). However, the decrease in yield was moderate, ranging between 62.6% and 72.6%. A high phenotypic variation was observed within each of the three sets of ABs under low nitrogen conditions, with some individuals displaying improved transgressive characteristics over the recurrent parents. Genotyping with the SPET 5k probes platform revealed a high, although variable, degree of recovery of the recurrent parent genome in the ABs and allowed the identification of 16 QTLs. Different allelic effects were observed for the introgressed QTL alleles. Several candidate genes were identified in the QTL regions associated with plant growth, yield, fruit size, and NUE-related parameters. Our results show that eggplant materials with introgressions from CWRs can result in a dramatic impact in eggplant breeding for a more sustainable agriculture.

genetics↗