Biology subjects

Peres, L.

Publications and source records attributed to Peres, L..

6 recordsLinked to original sources

bioRxiv2022

miR319-targeted TCP4/LANCEOLATE directly regulates OVATE and auxin responses to modulate tomato gynoecium patterning and fruit morphology

Diversity in fruit morphology is one of the hallmarks of varietal differences among modern cultivars of fruit-bearing crops. As evolutionarily related organs, fruits and leaves share developmental processes, but there are surprisingly few connections between regulatory pathways for fruit and leaf development. Here, we show the regulation of the leaf development-associated TEOSINTE BRANCHED1/CYCLOIDEA/PCF (TCP) TCP4/LANCEOLATE (TCP4/LA) transcription factor by the microRNA319 (miR319) is crucial for gynoecium patterning and establishment of fruit morphology. Loss of miR319 regulation leads to a premature, ectopic TCP4/LA expression during gynoecium patterning, which results in elongated fruits, resembling ovate mutants. TCP4/LA modulates tomato fruit development and morphology partially by directly repressing OVATE expression as early as 5-8 days post-inflorescence (dpi) flower buds. Furthermore, miR319-targeted CINCINNATA-like TCP4/LANCEOLATE controls auxin responses in developing flower buds by directly binding to the SlYUCCA4 promoter. Modulation of auxin biosynthesis by TCP4/LA is shared with other CINCINNATA-like TCPs during Arabidopsis gynoecium patterning. Our study defines a novel miRNA-based molecular link between OVATE, a fundamental gene associated with tomato domestication, and auxin responses in the control of fruit development and morphology. Given the striking variation in fruit shape among members of the Solanaceae family, fine-tuning regulation of gene expression by miRNA coupled with modulation of hormone dynamics may be a common driver in the evolution of fruit-shape diversity.

plant biology↗

bioRxiv2021

Auxin-driven ecophysiological diversification of leaves in domesticated tomato

Heterobaric leaves have bundle sheath extensions (BSEs) that compartmentalise the parenchyma, whereas homobaric leaves do not. The presence of BSEs affects leaf hydraulics and photosynthetic rate. The tomato (Solanum lycopersicum) obscuravenosa (obv) mutant lacks BSEs. Here we identify the obv gene and the causative mutation, a non-synonymous amino acid change that disrupts a C2H2 zinc finger motif in a putative transcription factor. This mutation exists as a rare polymorphism in the natural range of wild tomatoes, but has increased in frequency in domesticated tomatoes, suggesting that the latter diversified into heterobaric and homobaric leaf types. The obv mutant displays reduced vein density, leaf hydraulic conductance and photosynthetic assimilation rate. We show that these and other effects on plant development, including changes in leaf insertion angle, leaf margin serration, minor vein density and fruit shape, are controlled by OBV via changes in auxin signalling. Loss of function of the transcriptional regulator AUXIN RESPONSE FACTOR (ARF4) also results in defective BSE development, revealing an additional component of a novel genetic module controlling aspects of leaf development important for ecological adaptation and subject to breeding selection. One sentence summarydistribution of tomato heterobaric and homobaric leaves is controlled by a single-nucleotide polymorphism in an auxin-related transcription factor

plant biology↗

bioRxiv2021

Introgression of type-IV glandular trichomes from Solanum galapagense to cultivated tomato reveals genetic complexity for the development of acylsugar-based insect resistance

Glandular trichomes are involved in the production of food- and medicine-relevant chemicals in plants, besides being associated with pest resistance. In some wild Solanum species closely related to the cultivated tomato (S. lycopersicum), the presence of type-IV glandular trichomes leads to the production of high levels of insecticide acylsugars (AS). Conversely, low AS production observed in the cultivated tomato is attributed to its incapacity to develop type-IV trichomes in adult organs. Therefore, we hypothesized that cultivated tomatoes engineered to harbor type-IV trichomes on the leaves of mature plants can be pest resistant. We introgressed into the tomato cultivar Micro-Tom (MT) the capability of S. galapagense to maintain the development of type-IV trichomes throughout all plant stages, thus creating a line named "Galapagos enhanced trichomes" (MT-Get). Mapping-by-sequencing of MT-Get revealed that five chromosomal regions of S. galapagense were present in MT-Get. Further mapping reveled that S. galapagense alleles on chromosomes 1, 2 and 3 are sufficient for the presence of type-IV trichomes, but in lower densities. GC-MS, LC-MS, and gene expression analyses demonstrated that the increased density of type-IV trichomes was not accompanied by high AS production and exudation in MT-Get. Moreover, MT-Get did not differ from MT in its susceptibility to whitefly (Bemisia tabaci). Our findings demonstrates that type-IV glandular trichome development along with AS production and exudation are partially uncoupled at the genetic level. The MT-Get genotype represents a valuable resource for further studies involving the biochemical manipulation of type-IV trichome content through either genetic introgression or transgenic approaches. Significance StatementThis work identified loci in the tomato genome that control the heterochronic development of type-IV glandular trichomes and uncoupled the genetic control of this type of trichome ontogeny from acylsugar biosynthesis and accumulation, revealing a higher than anticipated genetic complexity of acylsugar-based insect resistance. The findings reported herein will contribute to further dissect the genetics of trichome development in tomato as well as to introgress broad and durable insect resistance in tomato and other Solanaceae.

plant biology↗

bioRxiv2021

The ORGAN SIZE (ORG) locus contributes to isometric gigantism in domesticated tomato

Gigantism is a key component of the domestication syndrome, a suite of traits that differentiates crops from their wild relatives. Allometric gigantism is strongly marked in horticultural crops, causing disproportionate increases in the size of edible parts such as stems, leaves or fruits. Tomato (Solanum lycopersicum) has attracted attention as a model for fruit gigantism, and many genes have been described controlling this trait. However, the genetic basis of a corresponding increase in size of vegetative organs contributing to isometric gigantism, has remained relatively unexplored. Here, we identified a 0.4 Mbp region on chromosome 7 in introgression lines (ILs) from the wild species Solanum pennellii in two different tomato genetic backgrounds (cv. M82 and cv. Micro-Tom) that controls vegetative and reproductive organ size in tomato. The locus, named ORGAN SIZE (ORG), was fine-mapped using genotype-by-sequencing. A survey of literature revealed that ORG overlaps with previously mapped QTLs controlling tomato fruit weight during domestication. Alleles from the wild species led to reduced cell number in different organs, which was partially compensated by greater cell expansion in leaves but not in fruits. The result was a proportional reduction in leaf, flower and fruit size in the ILs harbouring the wild alleles. These findings suggest that selection for large fruit during domestication also tends to select for increases in leaf size by influencing cell division. Since leaf size is relevant for both source-sink balance and crop adaptation to different environments, the discovery of ORG could allow fine-tuning of these parameters. One sentence summaryA locus that controls isometric size increase in vegetative and reproductive organs of tomato through changes in cell division

plant biology↗

bioRxiv2021

Photoperiod shapes aluminium tolerance in plants

Aluminium is a limiting factor for crop productivity in acidic soils (pH [≤] 5.5). Since acid soil distribution on Earth cannot adequately explain the differential Al tolerance across the plant kingdom, we investigated photoperiod effects on plant Al tolerance. We observed that with increasing distance from the equator, Al tolerance disappears, suggesting a relationship with the photoperiod. Long-day (LD) species are generally more Al-sensitive than short-day (SD) species, whereas genetic conversion of tomato for SD growth boosts Al tolerance. Reduced Al tolerance correlates with DNA-checkpoint activation under LD. DNA-checkpoint-related genes are under positive selection in Arabidopsis accessions from regions with shorter days, suggesting photoperiod acts as a selective barrier for Al tolerance. Our findings revealed that diel regulation and genetic diversity affect Al tolerance, suggesting that day-length orchestrates Al tolerance. One-Sentence SummaryAluminum is a major constraint for crop yield worldwide. We reveal that photoperiod acts as a barrier for Al tolerance in plants.

plant biology↗

bioRxiv2018

Convergent recruitment of life cycle regulators to direct sporophyte development in two eukaryotic supergroups

Three amino acid loop extension homeodomain transcription factors (TALE HD TFs) act as life cycle regulators in green algae and land plants. In mosses these regulators are required for the deployment of the sporophyte developmental program. We demonstrate that mutations in either of two TALE HD TF genes, OUROBOROS or SAMSARA, in the brown alga Ectocarpus result in conversion of the sporophyte generation into a gametophyte. The OUROBOROS and SAMSARA proteins heterodimerise in a similar manner to TALE HD TF life cycle regulators in the green lineage. These observations demonstrate that TALE-HD-TF-based life cycle regulation systems have an extremely ancient origin, and that these systems have been independently recruited to regulate sporophyte developmental programs in at least two different complex multicellular eukaryotic supergroups, Archaeplastida and Chromalveolata.

plant biology↗