Biology subjects

Perrone, I.

Publications and source records attributed to Perrone, I..

3 recordsLinked to original sources

bioRxiv2021

Molecular basis of differential adventitious rooting competence in poplar genotypes

O_LIRecalcitrant adventitious root (AR) development is a major hurdle in propagating commercially important woody plants. Although significant progress has been made to identify genes involved in subsequent steps of AR development, the molecular basis of differences in apparent recalcitrance to form AR between easy-to-root and difficult-to-root genotypes remains unknown. C_LIO_LITo address this, we generated cambium tissue-specific transcriptomic data from stem cuttings of hybrid aspen, T89 (difficult-to-root) and hybrid poplar OP42 (easy-to-root) and used transgenic approaches to verify the role of several transcription factors (TF) in the control of adventitious rooting. C_LIO_LIIncreased peroxidase activity is positively correlated with better rooting. We found differentially expressed genes encoding Reactive Oxygen Species (ROS) scavenging proteins to be enriched in OP42 compared to T89. A higher number of differentially expressed TF in OP42 compared to T89 cambium cells was revealed by a more intense transcriptional reprograming in the former. PtMYC2, a potential negative regulator, was less expressed in OP42 compared to T89. Using transgenic approaches, we have demonstrated that PttARF17.1 and PttMYC2.1 negatively regulate adventitious rooting. C_LIO_LIOur results provide insights into the molecular basis of genotypic differences in AR and implicate differential expression of the master regulator MYC2 as a critical player in this process. C_LI

plant biology↗

bioRxiv2020

Genomic structural variation in Nebbiolo grapevines at the individual, clonal and cultivar levels

Structural Variants (SVs) are a widely unexplored source of genetic variation, both due to methodological limitations and because they are generally associated to deleterious effects. However, with the advent of long-range genomic platforms, it has become easier to directly detect SVs. In the same direction, clonally propagated crops provide a unique opportunity to study SVs, offering a suitable genomic environment for their accumulation in heterozygosis. In particular, it has been reported that SVs generate drastic levels of heterozygosity in grapevines. Nebbiolo (Vitis vinifera L.) is a grapevine cultivar typical of north-western Italy, appreciated for its use in producing high-quality red wines. Here, we aimed to analyze the frequency of SVs in Nebbiolo, at three different organizational levels. For this purpose, we generated genomic data based on long-reads, linked-reads and optical mapping. We assembled a reference genome for this cultivar and compared two different clones, including V. vinifera reference genome (PN40024) in our comparisons. Our results indicate that SVs differentially occurring between Nebbiolo clones might be rare, while SVs differentiating haplotypes of the same individual are as abundant as those that occur differentially between cultivars.

genomics↗

bioRxiv2019

Molecular framework for TIR1/AFB-Aux/IAA-dependent auxin sensing controlling adventitious rooting in Arabidopsis

In Arabidopsis thaliana, canonical auxin-dependent gene regulation is mediated by 23 transcription factors from the AUXIN RESPONSE FACTOR (ARF) family, most of which interact with 29 auxin/indole acetic acid (Aux/IAA) repressors, themselves forming, in the presence of auxin, coreceptor complexes with one of six TRANSPORT INHIBITOR1/AUXIN-SIGNALLING F-BOX PROTEINS (TIR1/AFB). Different combinations of co-receptors drive specific sensing outputs, allowing auxin to control a myriad of processes. Considerable efforts have been made to discern the temporal and spatial specificity of auxin action. However, owing to a lack of obvious phenotype in single loss-of-function mutants in Aux/IAA genes, most genetic studies have relied on gain-of-function mutants, which are highly pleiotropic. In this article, we describe a molecular framework for the role of several members of the auxin sensing machinery. Using loss-of-function mutants, we demonstrate that TIR1 and AFB2 are positive regulators, whereas IAA6, IAA9 and IAA17 are negative regulators of adventitious root (AR) formation. The three Aux/IAA proteins interact with ARF6 and/or ARF8, which we have previously shown to be positive regulators of AR formation upstream of jasmonate, and likely repress their activity. Our data also suggest a dual role for TIR1 in the control of JA biosynthesis and conjugation, as revealed by upregulation of several JA biosynthesis genes in the tir1-1 mutant. In conclusion, we propose that in the presence of auxin, TIR1 and AFB2 form specific sensing complexes with IAA6, IAA9 and/or IAA17 that modulate JA homeostasis to control AR initiation.\n\nSignificanceAdventitious root (AR) formation is a quantitative trait with high phenotypic plasticity and auxin plays a major role in its control. In previous studies, we have shown that, in Arabidopsis hypocotyls, AR formation is negatively regulated by jasmonate, whose homeostasis is controlled by a regulatory module composed of three AUXIN RESPONSE FACTORS (ARF), two of which are positive regulators of three auxin inducible Gretchen Hagen3 (GH3) genes. The present work demonstrates that the two F-box proteins, i.e., TIR1 and AFB2, together with at least three Aux/IAA proteins are likely to interact in a combinatorial manner to control the activity of the two activator ARFs upstream of JA biosynthesis and/or homeostasis, thereby controlling AR initiation in Arabidopsis hypocotyls.

plant biology↗