Lucio Conti

University of Milan | UNIMI · Department of Bioscience

Plants align flowering with optimal seasonal conditions to increase reproductive success. This process depends on modulating signalling pathways that respond to diverse environmental and hormonal inputs, thereby regulating the transition to flowering at the shoot apical meristem. In Arabidopsis , long-day photoperiods (LDs) stimulate the transcript...

[This corrects the article DOI: 10.1371/journal.pgen.1010766.].

Early responses of plants to environmental stress factors prevent damage but can delay growth and development in fluctuating conditions. Optimising these trade‐offs requires tunability of plant responsiveness to environmental signals. We have previously reported that Histone Deacetylase Complex 1 (HDC1), which interacts with multiple proteins in hi...

The floral transition occurs at the shoot apical meristem (SAM) in response to favourable external and internal signals. Among these signals, variations in daylength (photoperiod) act as robust seasonal cues to activate flowering. In Arabidopsis, long-day photoperiods stimulate production in the leaf vasculature of a systemic florigenic signal that...

Water deficit conditions trigger the production of a chemical signal, the phytohormone abscisic acid (ABA), which coordinates multiple responses at different temporal and spatial scales. Despite the complexity of natural drought conditions, the modulation of ABA signaling could be harnessed to ameliorate the drought performances of crops in the fac...

We present unresolved questions in plant abiotic stress biology as posed by 15 research groups with expertise spanning eco-physiology to cell and molecular biology. Common themes of these questions include the need to better understand how plants detect water availability, temperature, salinity, and rising CO2 levels; how environmental signals inte...

Transcriptional reprogramming plays a key role in drought stress responses, preceding the onset of morphological and physiological acclimation. The best-characterised signal regulating gene expression in response to drought is the phytohormone abscisic acid (ABA). ABA-regulated gene expression, biosynthesis and signalling are highly organised in a...

Stomata are epidermal pores formed by pairs of specialized guard cells, which regulate gas exchanges between the plant and the atmosphere. Modulation of transcription has emerged as an important level of regulation of stomatal activity. The AtMYB60 transcription factor was previously identified as a positive regulator of stomatal opening, although...

Ultraviolet-B (UV–B) radiation as an environmental potential elicitor induces the synthesis of plant secondary metabolites. The effects of UV-B radiation on photosynthetic pigments and dry weight, biochemical and molecular features of old and young leaves of Salvia verticillata were investigated. Plants were exposed to 10.97 kJ m⁻² day⁻¹ of biologi...

Plants can react to drought stress by anticipating flowering, an adaptive strategy for plant survival in dry climates known as drought escape (DE). In Arabidopsis, the study of DE brought to surface the involvement of abscisic acid (ABA) in controlling the floral transition. A central question concerns how and in what spatial context can ABA signal...

Expansion of the maize growing area was central for food security in temperate regions. In addition to the suppression of the short-day requirement for floral induction, it required breeding for a large range of flowering time that compensates the effect of South-North gradients of temperatures. Here we show the role of a novel florigen gene, ZCN12...

The transition to flowering marks a key adaptive developmental switch in plants which impacts on their survival and fitness. Different signaling pathways control the floral transition, conveying both endogenous and environmental cues. These cues are often relayed and/or modulated by different hormones, which might confer additional developmental fl...

Key message: SUMOylation and anther growth. During fertilization, stamen elongation needs to be synchronized with pistil growth. The phytohormone gibberellic acid (GA) promotes stamen growth by stimulating the degradation of growth repressing DELLA proteins. DELLA accumulation is negatively regulated by GAs through the ubiquitin-proteasome system....

One strategy deployed by plants to endure water scarcity is to accelerate the transition to flowering adaptively via the drought escape (DE) response. In Arabidopsis thaliana, activation of the DE response requires the photoperiodic response gene GIGANTEA (GI) and the florigen genes FLOWERING LOCUS T (FT) and TWIN SISTER OF FT (TSF). The phytohormo...

Background Guard cells (GCs) are specialised cells within the plant epidermis which form stomatal pores, through which gas exchange can occur. The GCs derive through a specialised lineage of cell divisions which is specified by the transcription factor SPEECHLESS (SPCH), the expression of which can be detected in undifferentiated epidermal cells pr...

Small ubiquitin-like modifier proteases 1 and 2 (SUMO1/2) have been linked to the regulation of salicylic acid (SA)-mediated defence signalling in Arabidopsis thaliana. In order to define the role of the SUMO proteases OVERLY TOLERANT TO SALT1 and -2 (OTS1/2) in defence and to provide insight into SUMO1/2-mediated regulation of SA signalling, we ex...

Models for the control of above-ground plant architectures show how meristems can be programmed to be either shoots or flowers. Molecular, genetic, transgenic, and mathematical studies have greatly refined these models, suggesting that the phase of the shoot reflects different genes contributing to its repression of flowering, its vegetativeness ('...

Plants survive adversity by modulating their growth in response to changing environmental signals. The phytohormone Gibberellic acid (GA) plays a central role in regulating these adaptive responses by stimulating the degradation of growth repressing DELLA proteins which accumulate during stress. The current model for GA signalling describes how thi...

Plants use endogenous and environmental cues to trigger flowering. While variations in day length and temperature play a major role in controlling the transition to flowering, little is known about water stress-derived signals. Drought conditions cause early flowering in various plant species. Since it is well recognized that drought conditions als...

Plants maximize their chances to survive adversities by reprogramming their development according to environmental conditions. Adaptive variations in the timing to flowering reflect the need for plants to set seeds under the most favorable conditions. A complex network of genetic pathways allows plants to detect and integrate external (e.g., photop...

Plants survive adverse conditions by modulating their growth in response to a changing environment. Gibberellins (GAs) play a key role in these adaptive responses by stimulating the degradation of growth-repressing DELLA proteins. GA binding to its receptor GID1 enables association of GID1 with DELLAs. This leads to the ubiquitin-mediated proteasom...

Plants have evolved different strategies to resist drought, of which the best understood is the abscisic acid (ABA)-induced closure of stomatal pores to reduce water loss by transpiration. The availability of useful promoters that allow for precise spatial and temporal control of gene expression in stomata is essential both for investigating stomat...

Modulation of the transition to flowering plays an important role in the adaptation to drought. The drought escape (DE) response allows plants to adaptively shorten their life cycle to make seeds before severe stress leads to death. However, the molecular basis of DE response is unknown. The screen of different Arabidopsis thaliana flowering time m...

Drought and high salinity are two major abiotic stresses affecting crop productivity. Therefore, the development of crops better adapted to cope with these stresses represents a key goal to ensure global food security to an increasing world population. Although many genes involved in the response to these abiotic stresses have been extensively char...

We previously demonstrated that the Arabidopsis thaliana AtMYB60 protein is an R2R3MYB transcription factor required for stomatal opening. AtMYB60 is specifically expressed in guard cells and down-regulated at the transcriptional levels by the phytohormone ABA. To investigate the molecular mechanisms governing AtMYB60 expression, its promoter was d...

Occurrence of [A/T]AAAG motifs in the 300 bp regulatory region located upstream of the translational start codon of the AtMYB60, VvMYB30, VvMYB60 and VvSIRK genes. [A/T]AAAG nucleotides on the + strand are highlighted in yellow, whereas [A/T]AAAG nucleotides on the - strand are highlighted in pale blue. The predicted TATA box is in italic and highl...

Deduced gene structure of AtMYB60, VvMYB30 and VvMYB60. Boxes represent exons, while black lines represent introns. The location of the ATG start codon is indicated (black arrow). Gene organization and size of exons and introns were deduced by comparing the sequence of amplified genomic and cDNA fragments. Yellow and green boxes represent exon sequ...

Activity of the grape VvMYB360 and VvMYB60 promoters in flowers and siliques from Arabidopsis lines carrying promoter:GUS fusions. (A) GUS expression in pVvMYB30:GUS flowers was localized in carpels and stigmatic tissues (arrow). (B) Most pVvMYB60:GUS flowers did not show GUS activity, with the exception of two independent lines which disclosed sta...

Phenotypic changes in grapevine plantlets grown in the presence of growing NaCl concentration. Pictures were taken one month after the beginning of the treatment.

Generation and selection of the transgenic lines used for the complementation of the atmyb60-1 Arabidopsis mutant (atmyb60-C60 and atmyb60-C30). (A) and (B), schematic representation of the constructs used in the complementation test (not to scale). (C) and (D), RT-PCR analysis of transgene expression (VvMYB60 and VvMYB30) in three independent homo...

Under drought, plants accumulate the signaling hormone abscisic acid (ABA), which induces the rapid closure of stomatal pores to prevent water loss. This event is trigged by a series of signals produced inside guard cells which finally reduce their turgor. Many of these events are tightly regulated at the transcriptional level, including the contro...

Phytophthora infestans is the most destructive pathogen of potato and a model organism for the oomycetes, a distinct lineage of fungus-like eukaryotes that are related to organisms such as brown algae and diatoms. As the agent of the Irish potato famine in the mid-nineteenth century, P. infestans has had a tremendous effect on human history, result...

High salinity is an important factor limiting agriculture as major crops are salt sensitive. Understanding salt stress signalling is key to producing salt tolerant crops. The small ubiquitin-like modifier (SUMO) is a crucial regulator of signalling proteins in eukaryotes. Attachment of SUMO onto substrates is reversible and SUMO-proteases which spe...

Plant pathogens establish infection by secretion of effector proteins that may be delivered inside host cells to manipulate innate immunity. It is increasingly apparent that the ubiquitin proteasome system (UPS) contributes significantly to the regulation of plant defences and, as such, is a target for pathogen effectors. Bacterial effectors delive...

Understanding salt stress signaling is key to producing salt-tolerant crops. The small ubiquitin-like modifier (SUMO) is a crucial regulator of signaling proteins in eukaryotes. Attachment of SUMO onto substrates is reversible, and SUMO proteases, which specifically cleave the SUMO-substrate linkages, play a vital regulatory role during SUMOylation...

Shoot meristems harbor stem cells that provide key growing points in plants, maintaining themselves and generating all above-ground tissues. Cell-to-cell signaling networks maintain this population, but how are meristem and organ identities controlled? TERMINAL FLOWER1 (TFL1) controls shoot meristem identity throughout the plant life cycle, affecti...

Stomatal pores located on the plant epidermis regulate CO(2) uptake for photosynthesis and the loss of water by transpiration. The opening and closing of the pore is mediated by turgor-driven volume changes of two surrounding guard cells. These highly specialized cells integrate internal signals and environmental stimuli to modulate stomatal apertu...

Water deficit due to drought, high salt concentration and low temperature is one of the most important factor affecting the plants distribution on the earth surface. Identification of genes involved in mechanisms through which plants adapt to these adverse conditions is an important goal for future improvement of crop species in their tolerance to...