Convergent evolution of plant prickles by 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. In this work, 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 .

Dog training alleviates PTSD symptomatology by emotional and attentional regulation.

Background: Post-Traumatic Stress Disorder (PTSD) symptoms include re-experiencing, avoidance, hyperarousal, and cognitive deficits, reflecting both emotional and cognitive dysregulation. In recent years, non-pharmacological approaches and specifically animal-assisted therapy have been shown to be beneficial for a variety of disorders such as Attention-Deficit/Hyperactivity Disorder, Autism Spectrum Disorder, and PTSD. However, little is mentioned in the literature about the reciprocal effects of the animal-human interaction.

Synthesis of an Effective Flame-Retardant Hydrogel for Skin Protection Using Xanthan Gum and Resorcinol Bis(diphenyl phosphate)-Coated Starch.

We report on the production of a flame-resistant xanthan gum (XG)-based hydrogel formulation, which could be directly applied onto the skin for protection against burning projectiles. The hydrogel cream represents an efficient use of XG and starch, both of which are biodegradable, reusable natural materials and are also GRAS-certified. The flame-retardant agent resorcinol bis(diphenyl phosphate) (RDP) was shown to be nontoxic to cells in vitro when adsorbed directly onto the starch delivery vehicle.

Inhibition of gibberellin accumulation by water deficiency promotes fast and long-term 'drought avoidance' responses in tomato.

Plants reduce transpiration to avoid dehydration during drought episodes by stomatal closure and inhibition of canopy growth. Previous studies have suggested that low gibberellin (GA) activity promotes these 'drought avoidance' responses. Using genome editing, molecular, physiological and hormone analyses, we examined if drought regulates GA metabolism in tomato (Solanum lycopersicum) guard cells and leaves, and studied how this affects water loss.

Dissection of floral transition by single-meristem transcriptomes at high temporal resolution.

The vegetative-to-floral transition is a dramatic developmental change of the shoot apical meristem, promoted by the systemic florigen signal. However, poor molecular temporal resolution of this dynamic process has precluded characterization of how meristems respond to florigen induction. Here, we develop a technology that allows sensitive transcriptional profiling of individual shoot apical meristems.

Variation-set structure: Extraction of important segments in pigeon learning.

The ability to extract reliable segments from the sensory data-stream is necessary for learning and for creating a reliable representation of the environment. Here we focused on segmentation in visual learning associated with foraging. Fifty-one pigeons (Columba livia) were trained to recognize two food-predicting signals, one presented against fixed background elements and the other against varying backgrounds.

Conserved pleiotropy of an ancient plant homeobox gene uncovered by cis-regulatory dissection.

Divergence of gene function is a hallmark of evolution, but assessing functional divergence over deep time is not trivial. The few alleles available for cross-species studies often fail to expose the entire functional spectrum of genes, potentially obscuring deeply conserved pleiotropic roles. Here, we explore the functional divergence of WUSCHEL HOMEOBOX9 (WOX9), suggested to have species-specific roles in embryo and inflorescence development.

Major Impacts of Widespread Structural Variation on Gene Expression and Crop Improvement in Tomato.

Structural variants (SVs) underlie important crop improvement and domestication traits. However, resolving the extent, diversity, and quantitative impact of SVs has been challenging. We used long-read nanopore sequencing to capture 238,490 SVs in 100 diverse tomato lines.

Detection of Impending Aggressive Outbursts in Patients with Psychiatric Disorders: Violence Clues from Dogs.

Aggression in psychiatric wards is a continuing matter of concern for both patients and medical staff. Here we have tested the hypothesis that the frequency of such incidents can be reduced with a new strategy of using trained alert dogs that warn of impending violent outbursts. Dogs were positioned among patients in psychiatric wards.

Revolutions in agriculture chart a course for targeted breeding of old and new crops.

The dominance of the major crops that feed humans and their livestock arose from agricultural revolutions that increased productivity and adapted plants to large-scale farming practices. Two hormone systems that universally control flowering and plant architecture, florigen and gibberellin, were the source of multiple revolutions that modified reproductive transitions and proportional growth among plant parts. Although step changes based on serendipitous mutations in these hormone systems laid the foundation, genetic and agronomic tuning were required for broad agricultural benefits.

The flowering hormone florigen accelerates secondary cell wall biogenesis to harmonize vascular maturation with reproductive development.

Florigen, a proteinaceous hormone, functions as a universal long-range promoter of flowering and concurrently as a generic growth-attenuating hormone across leaf and stem meristems. In flowering plants, the transition from the vegetative phase to the reproductive phase entails the orchestration of new growth coordinates and a global redistribution of resources, signals, and mechanical loads among organs. However, the ultimate cellular processes governing the adaptation of the shoot system to reproduction remain unknown.

Bypassing Negative Epistasis on Yield in Tomato Imposed by a Domestication Gene.

Selection for inflorescence architecture with improved flower production and yield is common to many domesticated crops. However, tomato inflorescences resemble wild ancestors, and breeders avoided excessive branching because of low fertility. We found branched variants carry mutations in two related transcription factors that were selected independently.

Coordination of Meristem Doming and the Floral Transition by Late Termination, a Kelch Repeat Protein.

Enlargement and doming of the shoot apical meristem (SAM) is a hallmark of the transition from vegetative growth to flowering. While this change is widespread, its role in the flowering process is unknown. The () tomato () mutant shows severely delayed flowering and precocious doming of the vegetative SAM encodes a kelch domain-containing protein, with no link to known meristem maintenance or flowering time pathways.

Active suppression of a leaf meristem orchestrates determinate leaf growth.

Leaves are flat determinate organs derived from indeterminate shoot apical meristems. The presence of a specific leaf meristem is debated, as anatomical features typical of meristems are not present in leaves. Here we demonstrate that multiple NGATHA (NGA) and CINCINNATA-class-TCP (CIN-TCP) transcription factors act redundantly, shortly after leaf initiation, to gradually restrict the activity of a leaf meristem in to marginal and basal domains, and that their absence confers persistent marginal growth to leaves, cotyledons and floral organs.

Monopodial and sympodial branching architecture in cotton is differentially regulated by the Gossypium hirsutum SINGLE FLOWER TRUSS and SELF-PRUNING orthologs.

Domestication of upland cotton (Gossypium hirsutum) converted it from a lanky photoperiodic perennial to a day-neutral annual row-crop. Residual perennial traits, however, complicate irrigation and crop management, and more determinate architectures are desired. Cotton simultaneously maintains robust monopodial indeterminate shoots and sympodial determinate shoots.

Uncovering DELLA-Independent Gibberellin Responses by Characterizing New Tomato procera Mutants.

Gibberellin (GA) regulates plant development primarily by triggering the degradation/deactivation of the DELLA proteins. However, it remains unclear whether all GA responses are regulated by DELLAs. Tomato (Solanum lycopersicum) has a single DELLA gene named PROCERA (PRO), and its recessive pro allele exhibits constitutive GA activity but retains responsiveness to external GA.

Optimization of crop productivity in tomato using induced mutations in the florigen pathway.

Naturally occurring genetic variation in the universal florigen flowering pathway has produced major advancements in crop domestication. However, variants that can maximize crop yields may not exist in natural populations. Here we show that tomato productivity can be fine-tuned and optimized by exploiting combinations of selected mutations in multiple florigen pathway components.

Florigen and anti-florigen - a systemic mechanism for coordinating growth and termination in flowering plants.

Genetic studies in Arabidopsis established FLOWERING LOCUS T (FT) as a key flower-promoting gene in photoperiodic systems. Grafting experiments established unequivocal one-to-one relations between SINGLE FLOWER TRUSS (SFT), a tomato homolog of FT, and the hypothetical florigen, in all flowering plants. Additional studies of SFT and SELF PRUNING (SP, homolog of TFL1), two antagonistic genes regulating the architecture of the sympodial shoot system, have suggested that transition to flowering in the day-neutral and perennial tomato is synonymous with "termination.

Meristem maturation and inflorescence architecture--lessons from the Solanaceae.

Plant apical meristems (AMs) grow continuously by delicately balancing cells leaving at the periphery to form lateral organs with slowly dividing central domain cells that replenish reservoirs of pluripotent cells. This balance can be modified by signals originating from within and outside the meristem, and their integration results in a gradual maturation process that often culminates with the meristem differentiating into a flower. Accompanying this 'meristem maturation' are changes in spacing and size of lateral organs and in rates at which lateral meristems are released from apical dominance.

A cytokinin-activating enzyme promotes tuber formation in tomato.

Background: Dedicated storage organs in the form of tubers are evolutionary novelties that share a common function but originate in diverse species from different organs. Tubers in potato, Solanum tuberosum, are derived from the swollen tips of specialized basal lateral juvenile shoots, called stolons. Lateral buds of tomato, Solanum lycopersicum, a potato sibling species, only form regular shoots.

Dual regulation of ETTIN (ARF3) gene expression by AS1-AS2, which maintains the DNA methylation level, is involved in stabilization of leaf adaxial-abaxial partitioning in Arabidopsis.

Leaf primordia are generated at the periphery of the shoot apex, developing into flat symmetric organs with adaxial-abaxial polarity, in which the indeterminate state is repressed. Despite the crucial role of the ASYMMETRIC LEAVES1 (AS1)-AS2 nuclear-protein complex in leaf adaxial-abaxial polarity specification, information on mechanisms controlling their downstream genes has remained elusive. We systematically analyzed transcripts by microarray and chromatin immunoprecipitation assays and performed genetic rescue of as1 and as2 phenotypic abnormalities, which identified a new target gene, ETTIN (ETT)/AUXIN RESPONSE FACTOR3 (ARF3), which encodes an abaxial factor acting downstream of the AS1-AS2 complex.

Regulation of leaf maturation by chromatin-mediated modulation of cytokinin responses.

Plant shoots display indeterminate growth, while their evolutionary decedents, the leaves, are determinate. Determinate leaf growth is conditioned by the CIN-TCP transcription factors, which promote leaf maturation and are negatively regulated by miR319 in leaf primordia. Here we show that CIN-TCPs reduce leaf sensitivity to cytokinin (CK), a phytohormone implicated in inhibition of differentiation in the shoot.

Synchronization of the flowering transition by the tomato TERMINATING FLOWER gene.

The transition to flowering is a major determinant of plant architecture, and variation in the timing of flowering can have profound effects on inflorescence architecture, flower production and yield. Here, we show that the tomato mutant terminating flower (tmf) flowers early and converts the multiflowered inflorescence into a solitary flower as a result of precocious activation of a conserved floral specification complex encoded by ANANTHA (AN) and FALSIFLORA (FA). Without TMF, the coordinated flowering process is disrupted, causing floral identity genes, such as AN and members of the SEPALLATA (SEP) family, to activate precociously, while the expression of flowering transition genes, such as FRUITFULL (FUL), is delayed.

Failure of the tomato trans-acting short interfering RNA program to regulate AUXIN RESPONSE FACTOR3 and ARF4 underlies the wiry leaf syndrome.

Interfering with small RNA production is a common strategy of plant viruses. A unique class of small RNAs that require microRNA and short interfering (siRNA) biogenesis for their production is termed trans-acting short interfering RNAs (ta-siRNAs). Tomato (Solanum lycopersicum) wiry mutants represent a class of phenotype that mimics viral infection symptoms, including shoestring leaves that lack leaf blade expansion.