Kappelmccall4781

Sucrose controls various developmental and metabolic processes in plants. In this review, we evaluate whether sucrose could be a preferred signaling molecule that controls processes like carbohydrate metabolism, accumulation of storage proteins, sucrose transport, anthocyanin accumulation, and floral induction. We summarize putative sucrose-dependent signaling pathways. Sucrose, but not other sugars, stimulates the genes that encode ADP-glucose pyrophosphorylase (AGPase), granule-bound starch synthase I, and UDP-glucose pyrophosphorylase in several species. The class-1 patatin promoter is induced under high sucrose conditions in potato (Solanum tuberosum). Exogenous sucrose reduces the loading of sucrose to the phloem by inhibiting the expression of the sucrose transporter and its protein activity in sugar beet (Beta vulgaris). Sucrose also influences a wide range of growth processes, including cell division, ribosome synthesis, cotyledon development, far-red light signaling, and tuber development. Floral induction is promoted by sucrose in several species. The molecular mechanisms by which sucrose functions as a signal are largely unknown. Sucrose enhances the expression of transcription factors such as AtWRKY20 and MYB75, which function upstream of the sucrose-responsive genes. Sucrose controls the expression of AtbZIP11 at the post-transcriptional level by the peptide encoded by uORF2. Sucrose levels affect translation of a group of mRNAs in Arabidopsis. Sucrose increases the activity of AGPase by posttranslational redox-modification. Sucrose interrupts the interaction between sucrose transporter SUT4 and cytochrome b5. In addition, the SNF-related protein kinase-1 appears to be involved in sucrose-dependent pathways by controlling sucrose synthase (SUS4) expression.Pseudomonas syringae pv. tomato (Pst) is a pathogenic microorganism that causes bacterial speck disease and affects tomato yield and quality. Pto is a disease resistant gene for plant to recognize and defense against Pst. Pto interacts with Pti (Pto interacting) proteins, which include three transcription factors, Pti4, Pti5, Pti6, and they were thought to be downstream of Pto-mediated pathway to promote the expression of disease-related genes. In the present work, the overexpression plants of Pti4, Pti5 or Pti6 were obtained by Agrobacterium-mediated transformation in tomato. The Pti4/5/6-overexpressed lines indicated enhanced expression of pathogenesis-related genes and resistance to pathogenic bacteria Pst DC3000. Meanwhile, the transgenic plants showed that Pti4/5/6 function in ripening but performed no obvious adverse influence on flowering time, seed-setting rate, weight and soluble solids content of fruits. Furthermore, Pti-overexpressed fruits exhibited increased enzymatic activities of phenylalnine ammonialyase, catalase, peroxidase and decreased content of malondialdehyde. Additionally, cell-free and in vivo ubiquitination assay indicated that Pti4, Pti5 and Pti6 degraded by 26S proteasome which suggested that these Pti transcription regulators' functions could be regulated by ubiquitin-mediated post translational regulation in tomato.The ABI5 transcription factor, which is a core component of the ABA signaling pathway, affects various plant processes, including seed development and germination and responses to environmental cues. The knotted1-like homeobox (KNOX) transcription factor has crucial functions related to plant development, including the regulation of various hormones. In this study, an ABA-responsive KNOX gene, MdKNOX19, was identified in apple (Malus domestica). The overexpression of MdKNOX19 increased the ABA sensitivity of apple calli, resulting in a dramatic up-regulation in the transcription of the Arabidopsis ABI5-like MdABI5 gene. Additionally, MdKNOX19 overexpression in Micro-Tom adversely affected fruit size and seed yield as well as enhanced ABA sensitivity and up-regulated SlABI5 transcription during seed germination and early seedling development. An examination of MdKNOX19-overexpressing Arabidopsis plants also revealed severe defects in seed development and up-regulated expression of ABA-responsive genes. Furthermore, we further confirmed that MdKNOX19 binds directly to the MdABI5 promoter to activate expression. Our findings suggest MdKNOX19 is a positive regulator of ABI5 expression, and the conserved module MdKNOX19-MdABI5-ABA may contribute to organ development.This work presents the biochemical, cytochemical and molecular studies on two groups of PR proteins, β-1,3-glucanases and chitinases, and the arabinogalactan proteins (AGP) during the early stages of androgenesis induction in two breeding lines of rye (Secale cereale L.) with different androgenic potential. The process of androgenesis was initiated by tillers pre-treatments with low temperature, mannitol and/or reduced glutathione and resulted in microspores reprogramming and formation of androgenic structures what was associated with high activity of β-1,3-glucanases and chitinases. Some isoforms of β-1,3-glucanases, namely several acidic isoforms of about 26 kDa; appeared to be anther specific. Chitinases were well represented but were less variable. RT-qPCR revealed that the cold-responsive chitinase genes Chit1 and Chit2 were expressed at a lower level in the microspores and whole anthers while the cold-responsive Glu2 and Glu3 were not active. The stress pre-treatments modifications promoted the AGP accumulation. An apparent dominance of some AGP epitopes (LM2, JIM4 and JIM14) was detected in the androgenesis-responsive rye line. An abundant JIM13 epitopes in the vesicles and inner cell walls of the microspores and in the cell walls of the anther cell layers appeared to be the most specific for embryogenesis.Abscisic acid-responsive element (ABRE)-binding factors (ABFs) are important transcription factors involved in various physiological processes in plants. Stomata are micro channels for water and gas exchange of plants. Previous researches have demonstrated that ABFs can modulate the stomatal development in some plants. However, little is known about stomata-related functions of ABFs in carrots. In our study, DcABF3, a gene encoding for ABF transcription factor, was isolated from carrot. The open reading frame of DcABF3 was 1329 bp, encoding 442 amino acids. Expression profiles of DcABF3 indicated that DcABF3 can respond to drought, salt or ABA treatment in carrots. Overexpressing DcABF3 in Arabidopsis led to the increase of stomatal density which caused severe water loss. Expression assay indicated that overexpression of DcABF3 caused high expression of stomatal development-related transcription factor genes, SPCH, FAMA, MUTE and SCRMs. Increased antioxidant enzyme activities and higher expression levels of stress-related genes were also found in transgenic lines after water deficit treatment. Changes in expression of ABA synthesis-related genes and AtABIs indicated the potential role of DcABF3 in ABA signaling pathway. Under the treatment of exogenous ABA, DcABF3-overexpression Arabidopsis seedlings exhibited increased root length and germination rate. Our findings demonstrated that heterologous overexpression of DcABF3 positively affected stomatal development and also reduced ABA sensitivity in transgenic Arabidopsis.Phosphatidylcholine is a major phospholipid which is shown to be involved in stress adaptation. Phosphatidylcholine increased during dehydration in Craterostigma plantagineum, and therefore we characterized CTPphosphocholine cytidylyltransferase (CpCCT1), a key regulatory enzyme for phosphatidylcholine synthesis in plants. The CpCCT1 gene from the resurrection plant C. plantagineum was cloned and the amino acid sequence was compared with homologs from other species including yeast and rat. CCT proteins have conserved catalytic and membrane-binding domains while the N-terminal and C-terminal domains have diverged. The tissue specific expression analysis indicated that CpCCT1 is expressed in all tested tissues and it is induced by dehydration and in response to 0.5 M NaCl solutions. In plants exposed to low temperature in the dark, the CpCCT1 transcript increased after 4 h at 4 °C. CpCCT1 expression also increased during mannitol and sorbitol treatments in a concentration dependent manner. Phytohormones such as abscisic acid and indole-3-acetic acid also trigged transcript accumulation. Comparisons of transcript and protein accumulations for different treatments (except for dehydration) suggest transcriptional and translational control mechanisms. Analysis of promoter activity and polysome occupancy suggest that CpCCT1 gene expression is mainly under translational regulation during dehydration.Crops are continuously exposed to microbial pathogens that cause tremendous yield losses worldwide. Stomatal pores formed by pairs of specialized guard cells in the leaf epidermis represent a major route of pathogen entry. Guard cells have an essential role as a first line of defense against pathogens. Metabolomics is an indispensable systems biology tool that has facilitated discovery and functional studies of metabolites that regulate stomatal movement in response to pathogens and other environmental factors. Guard cells, pathogens and environmental factors constitute the "stomatal disease triangle". The aim of this review is to highlight recent advances toward understanding the stomatal disease triangle in the context of newly discovered signaling molecules, hormone crosstalk, and consequent molecular changes that integrate pathogens and environmental sensing into stomatal immune responses. Brequinar mouse Future perspectives on emerging single-cell studies, multiomics and molecular imaging in the context of stomatal defense are discussed. Advances in this important area of plant biology will inform rational crop engineering and breeding for enhanced stomatal defense without disruption of other pathways that impact crop yield.Anthocyanins are a group of secondary metabolites that protect plants from biotic and abiotic stresses. The research on anthocyanins has been well-received due to their colorfulness and human health benefits. In this study, we used the photosensitive eggplant cultivar 'Lanshan Hexian' as the research material and reported the functional characterization of SmMYB86, a negative regulator involved in the anthocyanin biosynthesis in eggplant. Our results suggested that SmMYB86 was a nuclear protein that was particularly expressed in leaves, stems, and peels. Overexpression of SmMYB86 in eggplant indicated that the accumulation of anthocyanins was reduced. Silencing of SmMYB86 in eggplant fruit peel significantly increased the anthocyanin content and expression levels of SmCHS, SmF3H, and SmANS. Yeast one-hybrid and dual-luciferase assays showed that SmMYB86 could directly bind to the promoters of SmCHS, SmF3H, and SmANS and suppress their activities. SmTTG1 binded to the promoter of SmCHS and promoted its activating. SmMYB86 interacted with SmTTG1 and inhibited its promotive role in SmCHS expression. This study provides some insights into the regulatory roles of SmMYB86 on key structural genes in the anthocyanin synthesis pathway in eggplant.Freezing stress is a major environmental factor that threatens the growth and development of fruit trees. MdMYB88 and its paralogue MdMYB124 have been identified as pivotal regulators in apple (Malus × domestica) freezing stress tolerance. Here, we demonstrated that a target of MdMYB88 and MdMYB124, TIME FOR COFFEE (TIC), contributes to freezing tolerance in apple. MdMYB88 and MdMYB124 directly bound the MdTIC promoter and positively regulated its expression under cold conditions. MdTIC RNAi plants displayed reduced freezing tolerance when MdTIC expression was repressed. Moreover, MdTIC RNAi plants lowered antioxidant enzyme activity. Transcriptome profiling revealed altered expression of cold-responsive genes in MdTIC RNAi plants under cold conditions, including MdPLC2, MdMKK2, and MdICE1. We also discovered that disordered MdTIC expression changed the saturation of fatty acids. Taken together, our data suggest that MdTIC is required for apple to tolerate freezing by mediating the expression of cold-responsive genes and fatty acid composition.