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1.
Ecotoxicol Environ Saf ; 236: 113437, 2022 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-35367878

RESUMO

Melatonin is a well-known signaling molecule that mediates a range of physiological activities and various stress reactions in plants. We comprehensively tested the effect of melatonin on the development of root hairs and glandular trichomes and found that melatonin pretreatment of tobacco seeds significantly increased the length of root hairs. Furthermore, melatonin-treated tobacco exhibited significantly higher density of trichomes and larger glandular heads on long-stalk glandular trichomes than untreated plants, which resulted in enhanced secretion in glandular trichomes. Exogenous melatonin enhanced the aphid resistance of plants by facilitating the accumulation of cembranoids in the glandular trichomes and alleviated cadmium toxicity by increasing the Cd-exudation capacity of long glandular trichomes. Metabolic analysis indicated that the contents of 108 metabolites significantly changed upon melatonin treatment, with the contents of those that are directly/indirectly involved in melatonin metabolism changing the most. Further, KEGG pathway analysis suggested that the metabolic pathways of amino acids, reducing sugar, secondary metabolites, indole alkaloid biosynthesis, purine, pyrimidine, and ABC transporters were greatly influenced by exogenous melatonin application. Moreover, metabolisms of melatonin-related antioxidants and pyrimidine nucleoside antibiotics were enhanced after melatonin treatment. Melatonin improved tobacco resistance to high salinity, drought, and extreme temperature stresses, as indicated by improved photosynthetic and antioxidant capacities in treated vs. untreated plants. This study lays a foundation for the comprehensive application of melatonin to increase the stress tolerance of plants.


Assuntos
Melatonina , Tricomas , Antioxidantes/metabolismo , Antioxidantes/farmacologia , Cádmio/metabolismo , Cádmio/toxicidade , Regulação da Expressão Gênica de Plantas , Melatonina/metabolismo , Melatonina/farmacologia , Folhas de Planta/metabolismo , Estresse Fisiológico , Tabaco/metabolismo , Tricomas/metabolismo
2.
BMC Plant Biol ; 22(1): 219, 2022 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-35477355

RESUMO

BACKGROUND: Mentha canadensis L. has important economic value for the production of essential oils, which are synthesised, secreted and stored in peltate glandular trichomes. As a typical multicellular secretory trichome, glandular trichomes are important biological factories for the synthesis of some specialised metabolites. However, little is known about the molecular mechanism of glandular trichome development in M. canadensis. RESULTS: In this study, the R2R3-MYB transcription factor gene McMIXTA was isolated to investigate its function in glandular trichome development. Bioinformatics analysis indicated that McMIXTA belonged to the subgroup 9 R2R3-MYB, with a R2R3 DNA-binding domain and conserved subgroup 9 motifs. A subcellular localisation assay indicated that McMIXTA was localised in the nucleus. Transactivation analysis indicated that McMIXTA was a positive regulator, with transactivation regions located between positions N253 and N307. Yeast two-hybrid and bimolecular fluorescence complementation assays showed that McMIXTA formed a complex with McHD-Zip3, a trichome development-related HD-ZIP IV transcription factor. Overexpression of McMIXTA in Mentha × piperita L. caused an increase in peltate glandular trichomes density of approximately 25% on the leaf abaxial surface. CONCLUSIONS: Our results demonstrated that the subgroup 9 R2R3-MYB transcription factor McMIXTA has a positive effect on regulating peltate glandular trichome development and the MIXTA/HD-ZIP IV complexes might be conserved regulators for glandular trichome initiation. These results provide useful information for revealing the regulatory mechanism of multicellular glandular trichome development.


Assuntos
Mentha , Óleos Voláteis , Óleos Voláteis/metabolismo , Folhas de Planta/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Tricomas/metabolismo
3.
Planta ; 255(5): 102, 2022 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-35412154

RESUMO

MAIN CONCLUSION: Glandular trichomes of Artemisia argyi H. Lév. & Vaniot are the key tissues for the production of flavonoid and terpenoid metabolites. Artemisia argyi H. Lév. & Vaniot is an herbaceous perennial plant that has been widely used in traditional medicine for thousands of years. Glandular trichomes (GTs) and nonglandular trichomes (NGTs) have been reported on the leaf surface of A. argyi. The aim of this study was to elucidate the morphogenetic process and to analyze the metabolites of trichomes in A. argyi. The morphogenesis of GTs and NGTs was characterized using light, scanning, and transmission electron microscopy. The constituents of GTs were analyzed using laser microdissection combined with gas and liquid chromatography-mass spectrometry. Five developmental stages of two types of GTs and four developmental stages of one type of NGTs were observed. Two types of mature GT and one type of NGT were composed of 10, 5, and 4-6 cells, respectively. A large storage cavity was detected between the cuticle and cell walls in the first type of mature GT. Large nuclei, nucleoli, and mitochondria were observed in the basal and intermediate cells of the second type of GT. In addition, large vacuoles were observed in the basal and apical cells, and large nuclei were observed in the middle cells of NGTs. One monoterpene and seven flavonoids were identified in GTs of A. argyi. We suggest that GTs are the key tissues for the production of bioactive metabolites in A. argyi. This study provides an important theoretical basis and technical approach for clarifying the regulatory mechanisms for trichome development and bioactive metabolite biosynthesis in A. argyi.


Assuntos
Artemisia , Tricomas , Artemisia/metabolismo , Flavonoides/análise , Morfogênese , Folhas de Planta/metabolismo , Terpenos/metabolismo , Tricomas/metabolismo
4.
Physiol Plant ; 174(2): e13666, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35285962

RESUMO

Exogenous methyl jasmonate (MeJA) treatment induces glandular trichome development in Nicotiana benthamiana, but the function of JAZ proteins, acting as core repressors, and their downstream genes have not been clearly shown in plants. Here, a bioinformatics analysis of 71 JAZ genes from tobacco, Arabidopsis thaliana, and tomato was carried out and shown to share highly conserved domains. Then, the expression profile of 17 NbJAZs in different tissues was analyzed, and NbJAZ3 was highly expressed in trichome. Through transgenic technology, we demonstrated that the glandular trichome density of NbJAZ3-overexpression lines significantly decreased with lower expression levels of NbWo, NbCycB2, and NbMIXTA. In contrast, the trichome density of NbJAZ3 RNAi lines slightly increased with higher expression level of NbWo. Given the negative protein feedback regulation relationship between NbCycB2 and NbWo, we verified that MeJA induced NbWo expression. NbWo was a direct target gene of NbJAZ3 and further demonstrated that NbJAZ3 inhibited the transcriptional activation of NbCycB2 by NbWo. Together, our findings outline a novel JA-meditated glandular trichome development model consisting of the NbJAZ3-NbWo-NbCycB2 axis.


Assuntos
Arabidopsis , Tabaco , Arabidopsis/genética , Ciclopentanos/metabolismo , Ciclopentanos/farmacologia , Regulação da Expressão Gênica de Plantas , Oxilipinas/metabolismo , Oxilipinas/farmacologia , Plantas Geneticamente Modificadas/genética , Tabaco/genética , Tabaco/metabolismo , Tricomas/genética , Tricomas/metabolismo
5.
Methods Mol Biol ; 2457: 393-407, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35349156

RESUMO

Plasmodesmata (PD) are channels in the walls of plant cells which enable cell-to-cell information transfer. This includes the selective transport of specific transcription factors that control cell fate during plant development. KNOTTED1 (KN1) homeobox (KNOX) family transcription factors that are essential for the maintenance and function of stem cells in shoot meristems use this trafficking pathway, but its mechanism is largely unknown. Here we describe a forward genetic approach to the identification of regulators of selective KN1 trafficking through PD, using a trichome rescue system that permits simple visual analysis in Arabidopsis leaves. A KN1 trafficking regulator identified in this approach had the capacity to regulate the transport not only of KN1 but also of another mobile regulatory protein, TRANSPARENT TESTA GLABRA1 (TTG1). Our system could be easily adapted to reveal the mechanism underlying the selective transport of additional mobile signals through PD.


Assuntos
Arabidopsis , Plasmodesmos , Arabidopsis/metabolismo , Proteínas de Homeodomínio/genética , Proteínas de Plantas/metabolismo , Plasmodesmos/metabolismo , Tricomas/genética , Tricomas/metabolismo
7.
Nat Commun ; 13(1): 1216, 2022 03 08.
Artigo em Inglês | MEDLINE | ID: mdl-35260555

RESUMO

Perception of pathogen-derived ligands by corresponding host receptors is a pivotal strategy in eukaryotic innate immunity. In plants, this is complemented by circadian anticipation of infection timing, promoting basal resistance even in the absence of pathogen threat. Here, we report that trichomes, hair-like structures on the epidermis, directly sense external mechanical forces, including raindrops, to anticipate pathogen infections in Arabidopsis thaliana. Exposure of leaf surfaces to mechanical stimuli initiates the concentric propagation of intercellular calcium waves away from trichomes to induce defence-related genes. Propagating calcium waves enable effective immunity against pathogenic microbes through the CALMODULIN-BINDING TRANSCRIPTION ACTIVATOR 3 (CAMTA3) and mitogen-activated protein kinases. We propose an early layer of plant immunity in which trichomes function as mechanosensory cells that detect potential risks.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Regulação da Expressão Gênica de Plantas , Imunidade Vegetal/genética , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Tricomas/fisiologia
8.
Methods Mol Biol ; 2379: 265-276, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35188667

RESUMO

A variety of methods for studying glandular leaf hairs (trichomes) as multicellular micro-organs are well established for synthetic biology platforms like tobacco or tomato but rather rare for nonglandular and usually single-celled trichomes of the model plant Arabidopsis thaliana. A thorough isolation of-ideally intact-trichomes is decisive for further biochemical and genomic analyses of primary and secondary metabolic compounds, enzymes, and especially transcripts to monitor initial success of an engineering approach. While isolation of tomato or tobacco trichomes is rather easy, by simply freezing whole plants in liquid nitrogen and brushing off trichomes, this approach does not work for Arabidopsis. This is mainly due to damage of trichome cells during the collection procedure and very low yield. Here, we provide a robust method for a virtually epithelial cell-free isolation of Arabidopsis trichomes. This method is then joined with an RNA isolation protocol to perform mRNA analysis on extracts of the isolated trichomes using a semi-quantitative RT-PCR setup.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , Regulação da Expressão Gênica de Plantas , Agricultura Molecular , Folhas de Planta/genética , Folhas de Planta/metabolismo , Biologia Sintética , Tricomas/genética , Tricomas/metabolismo
9.
Curr Opin Plant Biol ; 66: 102172, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35144142

RESUMO

Plant specialized metabolites are often synthesized and stored in dedicated morphological structures such as glandular trichomes, resin ducts, or laticifers where they accumulate in large concentrations. How this high productivity is achieved is still elusive, in particular, with respect to the interface between primary and specialized metabolism. Here, we focus on glandular trichomes to survey recent progress in understanding how plant metabolic cell factories manage to balance homeostasis of essential central metabolites while producing large quantities of compounds that constitute a metabolic sink. In particular, we review the role of gene duplications, transcription factors and photosynthesis.


Assuntos
Fotossíntese , Tricomas , Plantas/metabolismo , Alocação de Recursos , Fatores de Transcrição/metabolismo , Tricomas/genética , Tricomas/metabolismo
10.
Funct Plant Biol ; 49(4): 392-404, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35209991

RESUMO

Flowering and senescence are essential developmental stages of green plants, which are governed by complex molecular regulatory networks. However, the connection between flowering regulation and senescence regulation in London plane tree (Platanus acerifolia ) remains unknown. In this study, we identified a gene PaNAC089 from London plane tree, which encodes a membrane-tethered transcription factor (MTTF) belonging to the NAC (NAM, ATAF1/2, CUC2) transcription factor family. We investigated the functions of PaNAC089 in the regulation of flowering and senescence through the analysis of expression profiles and transgenic phenotypes. Heterologous overexpression of ΔPaNAC089 delayed flowering and inhibited chlorophyll breakdown to produce dark green rosette leaves in Arabidopsis . In addition, the trichome density of rosette leaves was decreased in transgenic lines. In ΔPaNAC089 overexpression plants, a series of functional genes with inhibited expression were identified by quantitative real-time polymerase chain reaction (qRT-PCR), including genes that regulate flowering, chlorophyll decomposition, and trichome initiation. Furthermore, Δ PaNAC089 directly binds to the promoter of CONSTANS (CO ) and NON-YELLOWING2 (NYE2 ) in the yeast one-hybrid assay. Consistent with this, luciferase (LUC) transient expression assays also showed that Δ PaNAC089 could inhibit the activity of NYE2 . To summarise, our data suggests that PaNAC089 is an MTTF that modulates flowering, chlorophyll breakdown and trichome initiation.


Assuntos
Fatores de Transcrição , Tricomas , Clorofila/metabolismo , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/genética , Plantas Geneticamente Modificadas/metabolismo , Fatores de Transcrição/genética , Tricomas/genética
11.
New Phytol ; 234(3): 902-917, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35167117

RESUMO

Tea trichomes synthesize numerous specialized metabolites to protect plants from environmental stresses and contribute to tea flavours, but little is known about the regulation of trichome development. Here, we showed that CsMYB1 is involved in the regulation of trichome formation and galloylated cis-catechins biosynthesis in tea plants. The variations in CsMYB1 expression levels are closely correlated with trichome indexes and galloylated cis-catechins contents in tea plant populations. Genome resequencing showed that CsMYB1 may be selected in modern tea cultivars, since a 192-bp insertion in CsMYB1 promoter was found exclusively in modern tea cultivars but not in the glabrous wild tea Camellia taliensis. Several enhancers in the 192-bp insertion increased CsMYB1 transcription in modern tea cultivars that coincided with their higher galloylated cis-catechins contents and trichome indexes. Biochemical analyses and transgenic data showed that CsMYB1 interacted with CsGL3 and CsWD40 and formed a MYB-bHLH-WD40 (MBW) transcriptional complex to activate the trichome regulator genes CsGL2 and CsCPC, and the galloylated cis-catechins biosynthesis genes anthocyanidin reductase and serine carboxypeptidase-like 1A. CsMYB1 integratively regulated trichome formation and galloylated cis-catechins biosynthesis. Results suggest that CsMYB1, trichome and galloylated cis-catechins are coincidently selected during tea domestication by harsh environments for improved adaption and by breeders for better tea flavours.


Assuntos
Catequina , Tricomas , Catequina/metabolismo , Domesticação , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Chá , Tricomas/metabolismo
12.
Int J Mol Sci ; 23(4)2022 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-35216041

RESUMO

The CAPRICE (CPC)-like (CPL) genes belong to a single-repeat R3 MYB family, whose roles in physic nut (Jatropha curcas L.), an important energy plant, remain unclear. In this study, we identified a total of six CPL genes (JcCPL1-6) in physic nut. The JcCPL3, 4, and 6 proteins were localized mainly in the nucleus, while proteins JcCPL1, 2, and 5 were localized in both the nucleus and the cytoplasm. Ectopic overexpression of JcCPL1, 2, and 4 in Arabidopsis thaliana resulted in an increase in root hair number and decrease in trichome number. Consistent with the phenotype of reduced anthocyanin in shoots, the expression levels of anthocyanin biosynthesis genes were down-regulated in the shoots of these three transgenic A. thaliana lines. Moreover, we observed that OeJcCPL1, 2, 4 plants attained earlier leaf senescence, especially at the late developmental stage. Consistent with this, the expression levels of several senescence-associated and photosynthesis-related genes were, respectively, up-regulated and down-regulated in leaves. Taken together, our results indicate functional divergence of the six CPL proteins in physic nut. These findings also provide insight into the underlying roles of CPL transcription factors in leaf senescence.


Assuntos
Antocianinas/biossíntese , Antocianinas/genética , Proteínas de Arabidopsis/genética , Arabidopsis/genética , Diferenciação Celular/genética , Expressão Ectópica do Gene/genética , /genética , Regulação da Expressão Gênica de Plantas/genética , Jatropha/genética , Plantas Geneticamente Modificadas/genética , Fatores de Transcrição/genética , Tricomas/genética
13.
Plant Physiol ; 189(1): 301-314, 2022 05 03.
Artigo em Inglês | MEDLINE | ID: mdl-35171294

RESUMO

Trichomes, the hair-like structures located on aerial parts of most vascular plants, are associated with a wide array of biological processes and affect the economic value of certain species. The processes involved in unicellular trichome formation have been well-studied in Arabidopsis (Arabidopsis thaliana). However, our understanding of the morphological changes and the underlying molecular processes involved in multicellular trichome development is limited. Here, we studied the dynamic developmental processes involved in glandular and nonglandular multicellular trichome formation in cucumber (Cucumis sativus L.) and divided these processes into five sequential stages. To gain insights into the underlying mechanisms of multicellular trichome formation, we performed a time-course transcriptome analysis using RNA-sequencing analysis. A total of 711 multicellular trichome-related genes were screened and a model for multicellular trichome formation was developed. The transcriptome and co-expression datasets were validated by reverse transcription-quantitative PCR and in situ hybridization. In addition, virus-induced gene silencing analysis revealed that CsHOMEOBOX3 (CsHOX3) and CsbHLH1 are involved in nonglandular trichome elongation and glandular trichome formation, respectively, which corresponds with the transcriptome data. This study presents a transcriptome atlas that provides insights into the molecular processes involved in multicellular trichome formation in cucumber and can be an important resource for future functional studies.


Assuntos
Arabidopsis , Cucumis sativus , Arabidopsis/genética , Cucumis sativus/genética , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Transcriptoma/genética , Tricomas/genética
14.
Plant Sci ; 317: 111172, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35193735

RESUMO

Glandular trichomes can secrete and store a large number of secondary metabolites in plants, some of which are of high medicinal and commercial value. For example, artemisinin, isolated from Artemisia annua L. plants, and its derivatives have great high medicinal value. Previous research indicated that artemisinin was synthesized in the glandular trichomes on the leaves of A. annua. It is an important study direction to improve artemisinin yield by promoting the initiation and development of glandular trichome. In this study, SQUAMOSA promoter-binding protein-like 9 (AaSPL9) was identified. In AaSPL9 overexpression transgenic plants, the glandular trichomes density was increased by 45-60 %, and the content of artemisinin was increased by 33-60 %, indicating that AaSPL9 positively regulate the glandular trichomes initiation. Yeast one-hybrid(Y1H), Dual-luciferase (Dual-Luc), Electrophoretic Mobility Shift Assay (EMSA) demonstrated that AaSPL9 activated the expression of AaHD1 by combining directly the GTAC-box of the AaHD1 promoter. Taken together, we identified AaSPL9, a positive transcription factor, regulating the glandular trichome initiation in A. annua, and revealed a novel molecular mechanism by which a SPL protein to promote glandular trichome initiation.


Assuntos
Artemisia annua , Artemisia annua/genética , Artemisia annua/metabolismo , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/metabolismo , Tricomas/metabolismo
15.
Gene ; 820: 146308, 2022 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-35150819

RESUMO

Trichomes exhibit extraordinary diversity in shape, ultrastructure, distribution, secretion capability, biological functions, and morphological differences, which are strongly associated with their multifunction. Previous researches showed MIXTA-like transcription factors involved in regulating trichome initiation and patterning via forming MYB-bHLH-WD40 transcriptional activator complex to induce the expression of downstream genes. Here, we report the characteristics and role of GhMML1 and GhMML2, members of subgroup 9 of the R2R3-type MYB TFs. GhMML1 and GhMML2 were preferentially targeted to the nucleus and prominently expressed in the early stage during fiber development. Ectopic expression of GhMML1 and GhMML2 respectively in the transgenic tobacco plants changed the morphological characteristics of leaf trichomes; that is, the unbranched trichomes turned into multiple branched, and in the meantime, the density of trichomes was reduced on the surface of the leaf. Y2H and LCI assay revealed that both GhMML1 and GhMML2 could physically interact with a bZIP transcription factor family protein (GhbZIP) in vivo and in vitro. It has been reported that GhbZIP's homolog TAG3 in Arabidopsis is involved in the asymmetric growth of leaves and flowers via direct interaction with BOP1. Taken together, our results demonstrated that two MYB MIXTA-like proteins, GhMML1 and GhMML2, together with GhbZIP might form a multimeric complex to involve in trichome development. This study highlights the importance of MIXTA-like genes from TF subgroup 9 and will help to uncover the molecular mechanism underlying differential trichomes and their development.


Assuntos
Fatores de Transcrição de Zíper de Leucina Básica/genética , Fatores de Transcrição de Zíper de Leucina Básica/metabolismo , Gossypium/genética , Tabaco/genética , Tabaco/metabolismo , Tricomas/genética , Tricomas/metabolismo , Regulação da Expressão Gênica de Plantas , Morfogênese , Filogenia , Folhas de Planta/genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo
16.
New Phytol ; 234(1): 179-196, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35023174

RESUMO

The fruit surface has an enormous impact on the external appearance and postharvest shelf-life of fruit. Here, we report two functionally redundant genes, PpMYB25 and PpMYB26, involved in regulation of fruit skin texture in peach. PpMYB25 can activate transcription of PpMYB26 and they both induce trichome development and cuticular wax accumulation, resulting in peach fruit with a fuzzy and dull appearance. By contrast, nonfunctional mutation of PpMYB25 caused by an insertional retrotransposon in the last exon in nectarine fails to activate transcription of PpMYB26, resulting in nectarine fruit with a smooth and shiny appearance due to loss of trichome initiation and decreased cuticular wax accumulation. Secondary cell wall biosynthesis in peach fruit pubescence is controlled by a transcriptional regulatory network, including the master regulator PpNAC43 and its downstream MYB transcription factors such as PpMYB42, PpMYB46 and PpMYB83. Our results show that PpMYB25 and PpMYB26 coordinately regulate fruit pubescence and cuticular wax accumulation and their simultaneous perturbation results in the origin of nectarine, which is botanically classified as a subspecies of peach.


Assuntos
Prunus persica , Frutas , Regulação da Expressão Gênica de Plantas , Genes myb , Prunus persica/genética , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Tricomas/genética , Tricomas/metabolismo
17.
J Exp Bot ; 73(4): 1155-1175, 2022 02 24.
Artigo em Inglês | MEDLINE | ID: mdl-35038724

RESUMO

Raindrop impact on leaves is a common event which is of relevance for numerous processes, including the dispersal of pathogens and propagules, leaf wax erosion, gas exchange, leaf water absorption, and interception and storage of rainwater by canopies. The process of drop impact is complex, and its outcome depends on many influential factors. The wettability of plants has been recognized as an important parameter which is itself complex and difficult to determine for leaf surfaces. Other important parameters include leaf inclination angle and the ability of leaves to respond elastically to drop impact. Different elastic motions are initiated by drop impact, including local deformation, flapping, torsion, and bending, as well as 'swinging' of the petiole. These elastic responses, which occur on different time scales, can affect drop impact directly or indirectly, by changing the leaf inclination. An important feature of drop impact is splashing, meaning the fragmentation of the drop with ejection of satellite droplets. This process is promoted by the kinetic energy of the drop and leaf traits. For instance, a dense trichome cover can suppress splashing. Basic drop impact patterns are presented and discussed for a number of different leaf types, as well as some exemplary mosses.


Assuntos
Folhas de Planta , Chuva , Folhas de Planta/fisiologia , Plantas , Tricomas , Molhabilidade
18.
Plant Physiol ; 188(3): 1563-1585, 2022 03 04.
Artigo em Inglês | MEDLINE | ID: mdl-34986267

RESUMO

Arabidopsis (Arabidopsis thaliana) root hairs develop as long tubular extensions from the rootward pole of trichoblasts and exert polarized tip growth. The establishment and maintenance of root hair polarity is a complex process involving the local apical production of reactive oxygen species generated by A. thaliana nicotinamide adenine dinucleotide phosphate (NADPH) oxidase respiratory burst oxidase homolog protein C/ROOT HAIR-DEFECTIVE 2 (AtRBOHC/RHD2). Loss-of-function root hair defective 2 (rhd2) mutants have short root hairs that are unable to elongate by tip growth, and this phenotype is fully complemented by GREEN FLUORESCENT PROTEIN (GFP)-RHD2 expressed under the RHD2 promoter. However, the spatiotemporal mechanism of AtRBOHC/RHD2 subcellular redistribution and delivery to the plasma membrane (PM) during root hair initiation and tip growth are still unclear. Here, we used advanced microscopy for detailed qualitative and quantitative analysis of vesicular compartments containing GFP-RHD2 and characterization of their movements in developing bulges and growing root hairs. These compartments, identified by an independent molecular marker mCherry-VTI12 as the trans-Golgi network (TGN), deliver GFP-RHD2 to the apical PM domain, the extent of which corresponds with the stage of root hair formation. Movements of TGN/early endosomes, but not late endosomes, were affected in the bulging domains of the rhd2-1 mutant. Finally, we revealed that structural sterols might be involved in the accumulation, docking, and incorporation of TGN compartments containing GFP-RHD2 to the apical PM of root hairs. These results help in clarifying the mechanism of polarized AtRBOHC/RHD2 targeting, maintenance, and recycling at the apical PM domain, coordinated with different developmental stages of root hair initiation and growth.


Assuntos
Arabidopsis/crescimento & desenvolvimento , Arabidopsis/genética , Membrana Celular/metabolismo , Organogênese Vegetal/genética , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/genética , Tricomas/crescimento & desenvolvimento , Membrana Celular/genética , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Variação Genética , Genótipo , Mutação , Tricomas/genética
19.
New Phytol ; 233(6): 2643-2658, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35037268

RESUMO

Fruit spine is an important trait in cucumber, affecting not only commercial quality, but also fruit smoothness, transportation and storage. Spine size is determined by a multi-cellular base. However, the molecular mechanism underlying the regulation of cucumber spine base remains largely unknown. Here, we report map-based cloning and characterization of a spine base size 1 (SBS1) gene, encoding a C2H2 zinc-finger transcription factor. Near-isogenic lines of cucumber were used to map, identify and quantify cucumber spine base size 1 (CsSBS1). Yeast-hybrid, bimolecular fluorescence complementation (BiFC), co-immunoprecipitation (Co-IP) and RNA-sequencing assays were used to explore the molecular mechanism of CsSBS1 in regulating spine base size development. CsSBS1 was specifically expressed in cucumber ovaries with particularly high expression in fruit spines. Overexpression of CsSBS1 resulted in large fruit spine base, while RNA-interference silencing of CsSBS1 inhibited the expansion of fruit spine base. Sequence analysis of natural cucumber accessions revealed that CsSBS1 was lost in small spine base accessions, resulting from a 4895 bp fragment deletion in CsSBS1 locus. CsSBS1 can form a trimeric complex with two positive regulators CsTTG1 and CsGL1 to regulate spine base development through ethylene signaling. A novel regulator network is proposed that the CsGL1/CsSBS1/CsTTG1 complex plays a significant role in regulating spine base formation and size, which offers a strategy for cucumber breeders to develop smooth fruit.


Assuntos
Cucumis sativus , Cucumis sativus/metabolismo , Frutas , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Tricomas/metabolismo
20.
New Phytol ; 233(5): 2036-2046, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-34704619

RESUMO

Trichomes and cuticles are key protective epidermal specializations. This review highlights the genetic interplay existing between trichome and cuticle formation in a variety of species. Controlling trichome development, the biosynthesis of trichome-derived specialized metabolites as well as cuticle biosynthesis and deposition can be viewed as different aspects of a common defensive strategy adopted by plants to protect themselves from environmental stresses. Existence of such interplay is based on the mining of published transcriptomic data as well as on phenotypic observations in trichome or cuticle mutants where the morphology of both structures often appear to be concomitantly altered. Given the existence of several trichome developmental pathways depending on the plant species and the types of trichomes, genetic interactions between cuticle formation and trichome development are complex to decipher and not easy to generalize. Based on our review of the literature, a schematic overview of the gene network mediating this transcriptional interplay is presented for two model plant species: Arabidopsis thaliana and Solanum lycopersicum. In addition to fundamental new insights on the regulation of these processes, identifying key transcriptional switches controlling both processes could also facilitate more applied investigations aiming at improving much desired agronomical traits in plants.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Lycopersicon esculentum , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Regulação da Expressão Gênica de Plantas , Lycopersicon esculentum/genética , Lycopersicon esculentum/metabolismo , Tricomas/metabolismo
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