scholarly journals Taxonomic study on Lindernia All. (Linderniaceae) from some parts of South Eastern Nigeria

2020 ◽  
Vol 12 (2) ◽  
pp. 301-317
Author(s):  
Chimezie EKEKE ◽  
Chinedum A. OGAZIE ◽  
Cornelius O. NICHODEMUS

The morpho-anatomical characteristics of Lindernia diffusa var. diffusa-in E. & P., L. oliveriana (Benth.) Wettst. and L. crustacea (L.) F. Muell.) were investigated with a view of providing additional line of evidence in the delimitation of the species in Nigeria. The specimens were subjected to microtomy. The anatomy, fruit morphology, leaf shape, number of fruits per node and, flower colour differed among the species. The species have two trichome types (glandular and non-glandular) with varying number of gland head and basal cells. The glandular trichomes have 4-7 gland heads and 4-8 basal cells while the non-glandular type-1 and 2 trichomes with 5-10 basal cells. Type-1 non-glandular trichome occurred in L. crustacean and L. diffusa var. diffusa while type-2 occurred in L. oliveriana. The palisade and spongy mesophylls are 1-layer and 3-5 layers respectively in L. diffusa var. diffusa, 1-2 layers and 4-6 layers in L. oliveriana and 2-3 layers and3 layers in L. crustacea. The palisade and spongy mesophylls are poorly differentiated. Two to five vascular bundles at the basal and distal ends of the petioles were observed in the Lindernia species with the main vascular bundle forming circular-united or fussed vascular bundles in L. diffusa var. diffusa and L. crustacea and arced or horizontally elongated vascular bundle separated by parenchymatous rays in L. oliveriana. In L. diffusa var. diffusa, the pith covered 55.99% of the stem, 24.27% in L. crustacea and 72.74% in L. oliveriana. These characters could be used to delimit the species studied.

Euphytica ◽  
2021 ◽  
Vol 217 (3) ◽  
Author(s):  
Joris Santegoets ◽  
Marcella Bovio ◽  
Wendy van’t Westende ◽  
Roeland E. Voorrips ◽  
Ben Vosman

AbstractThe greenhouse whitefly Trialeurodes vaporariorum is a major threat in tomato cultivation. In greenhouse grown tomatoes non-trichome based whitefly resistance may be better suited than glandular trichome based resistance as glandular trichomes may interfere with biocontrol, which is widely used. Analysis of a collection of recombinant inbred lines derived from a cross between Solanum lycopersicum and Solanum galapagense showed resistance to the whitefly T. vaporariorum on plants without glandular trichomes type IV. The resistance affected whitefly adult survival (AS), but not oviposition rate. This indicates that S. galapagense, in addition to trichome based resistance, also carries non-trichome based resistance components. The effectiveness of the non-trichome based resistance appeared to depend on the season in which the plants were grown. The resistance also had a small but significant effect on the whitefly Bemisia tabaci, but not on the thrips Frankliniella occidentalis. A segregating F2 population was created to map the non-trichome based resistance. Two Quantitative trait loci (QTLs) for reduced AS of T. vaporariorum were mapped on chromosomes 12 and 7 (explaining 13.9% and 6.0% of the variance respectively). The QTL on chromosome 12 was validated in F3 lines.


Plants ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 930
Author(s):  
Xu Yu ◽  
Xiwu Qi ◽  
Shumin Li ◽  
Hailing Fang ◽  
Yang Bai ◽  
...  

Light is a key environmental aspect that regulates secondary metabolic synthesis. The essential oil produced in mint (Mentha canadensis L.) leaves is used widely in the aromatics industry and in medicine. Under low-light treatment, significant reductions in peltate glandular trichome densities were observed. GC-MS analysis showed dramatically reduced essential oil and menthol contents. Light affected the peltate glandular trichomes’ development and essential oil yield production. However, the underlying mechanisms of this regulation were elusive. To identify the critical genes during light-regulated changes in oil content, following a 24 h darkness treatment and a 24 h recovery light treatment, leaves were collected for transcriptome analysis. A total of 95,579 unigenes were obtained, with an average length of 754 bp. About 56.58% of the unigenes were annotated using four public protein databases: 10,977 differentially expressed genes (DEGs) were found to be involved in the light signaling pathway and monoterpene synthesis pathway. Most of the TPs showed a similar expression pattern: downregulation after darkness treatment and upregulation after the return of light. In addition, the genes involved in the light signal transduction pathway were analyzed. A series of responsive transcription factors (TFs) were identified and could be used in metabolic engineering as an effective strategy for increasing essential oil yields.


Plants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1420
Author(s):  
Takahiro Ueda ◽  
Miki Murata ◽  
Ken Yokawa

Environmental light conditions influence the biosynthesis of monoterpenes in the mint plant. Cyclic terpenes, such as menthol, menthone, pulegone, and menthofuran, are major odor components synthesized in mint leaves. However, it is unclear how light for cultivation affects the contents of these compounds. Artificial lighting using light-emitting diodes (LEDs) for plant cultivation has the advantage of preferential wavelength control. Here, we monitored monoterpene contents in hydroponically cultivated Japanese mint leaves under blue, red, or far-red wavelengths of LED light supplements. Volatile cyclic monoterpenes, pulegone, menthone, menthol, and menthofuran were quantified using the head-space solid phase microextraction method. As a result, all light wavelengths promoted the biosynthesis of the compounds. Remarkably, two weeks of blue-light supplement increased all compounds: pulegone (362% increase compared to the control), menthofuran (285%), menthone (223%), and menthol (389%). Red light slightly promoted pulegone (256%), menthofuran (178%), and menthol (197%). Interestingly, the accumulation of menthone (229%) or menthofuran (339%) was observed with far-red light treatment. The quantification of glandular trichomes density revealed that no increase under light supplement was confirmed. Blue light treatment even suppressed the glandular trichome formation. No promotion of photosynthesis was observed by pulse-amplitude-modulation (PAM) fluorometry. The present result indicates that light supplements directly promoted the biosynthetic pathways of cyclic monoterpenes.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Peina Zhou ◽  
Mengjiao Yin ◽  
Shilin Dai ◽  
Ke Bao ◽  
Chenglin Song ◽  
...  

Abstract Background Perilla frutescens (L.) Britt is a medicinal and edible plant widely cultivated in Asia. Terpenoids, flavonoids and phenolic acids are the primary source of medicinal ingredients. Glandular trichomes with multicellular structures are known as biochemical cell factories which synthesized specialized metabolites. However, there is currently limited information regarding the site and mechanism of biosynthesis of these constituents in P. frutescens. Herein, we studied morphological features of glandular trichomes, metabolic profiling and transcriptomes through different tissues. Results Observation of light microscopy and scanning electron microscopy indicated the presence of three distinct glandular trichome types based on their morphological features: peltate, capitate, and digitiform glandular trichomes. The oil of peltate glandular trichomes, collected by custom-made micropipettes and analyzed by LC–MS and GC–MS, contained perillaketone, isoegomaketone, and egomaketone as the major constituents which are consistent with the components of leaves. Metabolomics and transcriptomics were applied to explore the bioactive constituent biosynthesis in the leaves, stem, and root of P. frutescens. Transcriptome sequencing profiles revealed differential regulation of genes related to terpenoids, flavonoids, and phenylpropanoid biosynthesis, respectively with most genes expressed highly in leaves. The genes affecting the development of trichomes were preliminarily predicted and discussed. Conclusions The current study established the morphological and chemical characteristics of glandular trichome types of P. frutescens implying the bioactive constituents were mainly synthesized in peltate glandular trichomes. The genes related to bioactive constituents biosynthesis were explored via transcriptomes, which provided the basis for unraveling the biosynthesis of bioactive constituents in this popular medicinal plant.


2021 ◽  
Vol 22 (7) ◽  
pp. 3347
Author(s):  
Mengyi Chen ◽  
Xiaoyang Zhu ◽  
Xiaojuan Liu ◽  
Caiyu Wu ◽  
Canye Yu ◽  
...  

Auxin response factors (ARFs) play important roles in various plant physiological processes; however, knowledge of the exact role of ARFs in plant responses to water deficit is limited. In this study, SlARF4, a member of the ARF family, was functionally characterized under water deficit. Real-time fluorescence quantitative polymerase chain reaction (PCR) and β-glucuronidase (GUS) staining showed that water deficit and abscisic acid (ABA) treatment reduced the expression of SlARF4. SlARF4 was expressed in the vascular bundles and guard cells of tomato stomata. Loss of function of SlARF4 (arf4) by using Clustered Regularly Interspaced Short Palindromic Repeats/Cas 9 (CRISPR/Cas 9) technology enhanced plant resistance to water stress and rehydration ability. The arf4 mutant plants exhibited curly leaves and a thick stem. Malondialdehyde content was significantly lower in arf4 mutants than in wildtype plants under water stress; furthermore, arf4 mutants showed higher content of antioxidant substances, superoxide dismutase, actual photochemical efficiency of photosystem II (PSII), and catalase activities. Stomatal and vascular bundle morphology was changed in arf4 mutants. We identified 628 differentially expressed genes specifically expressed under water deficit in arf4 mutants; six of these genes, including ABA signaling pathway-related genes, were differentially expressed between the wildtype and arf4 mutants under water deficit and unlimited water supply. Auxin responsive element (AuxRE) elements were found in these genes’ promoters indicating that SlARF4 participates in ABA signaling pathways by regulating the expression of SlABI5/ABF and SCL3, thereby influencing stomatal morphology and vascular bundle development and ultimately improving plant resistance to water deficit.


1993 ◽  
Vol 106 (1) ◽  
pp. 45-53 ◽  
Author(s):  
C.S. Chen ◽  
B. Lyons-Giordano ◽  
G.S. Lazarus ◽  
P.J. Jensen

Using immunohistochemistry and in situ hybridization, we have characterized the expression and localization of components of the plasminogen activator proteolytic cascade in an organotypic coculture system which consists of a “dermal” portion (human dermal fibroblasts throughout a collagen matrix) and a stratified, well-differentiated epidermal portion. Specifically, the following components were examined: the enzymes urokinase-type plasminogen activator and tissue-type plasminogen activator and their type 1 and type 2 inhibitors. Urokinase plasminogen activator mRNA and antigen were found predominantly in the least differentiated, basal keratinocytes; in some fields there was also faint deposition of antigen beneath the basal cells. The distribution of plasminogen activator inhibitor type 1 was similar to that of urokinase, except that inhibitor type 1 antigen deposition beneath the basal cells appeared more intense and uniform. In contrast to the results with urokinase plasminogen activator and inhibitor type 1, tissue plasminogen activator mRNA and antigen were localized focally in the suprabasal, i.e. more differentiated, keratinocytes. Plasminogen activator inhibitor type 2 mRNA and antigen were detected in most epidermal layers, but were more intense suprabasally and often spared the basal layer. These studies demonstrate that the same type of cell, i.e. the keratinocyte, can express different components of the plasminogen activator cascade depending on its state of differentiation. The change in expression of plasminogen activator cascade components with keratinocyte differentiation suggests distinct epidermal functions for these components, related to cell-matrix interaction and epidermal differentiation.


2002 ◽  
Vol 62 (1) ◽  
pp. 179-185 ◽  
Author(s):  
G. F. A. MELO DE PINNA ◽  
J. E. KRAUS ◽  
N. L. de MENEZES

The leaf mine in Richterago riparia is caused by a lepidopteran larva (lepidopteronome). The leaves of R. riparia show campdodrome venation; the epidermis is unistratified, with stomata and glandular trichomes in adaxial and abaxial surfaces. The mesophyll is bilateral and the vascular system is collateral. During the formation of the mine, the larva consumes the chlorenchyma of the mesophyll and the smaller vascular bundles (veins of third and fourth orders). Structural alterations in the tissues of the host plant were not observed, except for the formation of a wound meristem and the presence of cells with phenolic substances next to the mine. Three cephalic exuviae of the miner were found in the mesophyll. This lepidopteronome is parenchymatic and the epidermis remains intact, but forms a protective layer for the mining insect.


1997 ◽  
Vol 122 (3) ◽  
pp. 373-379 ◽  
Author(s):  
Richard Grazzini ◽  
Donald Walters ◽  
Jody Harmon ◽  
David J. Hesk ◽  
Diana Cox-Foster ◽  
...  

Diploid zonal geraniums (Pelargonium ×hortorum) are able to resist attack by small arthropod pests such as the two-spotted spider mite (Tetranychus urticae Koch) when exudate produced by tall glandular trichomes contains a high percentage of ω5-unsaturated anacardic acids. Trichomes of susceptible plants exude primarily saturated anacardic acids. Inbred mite-resistant and -susceptible geraniums were reciprocally crossed and the F1, F2, and backcross generations were examined for anacardic acid composition and trichome density. Selected F2 plants were bioassayed for resistance to two-spotted spider mites. High concentrations of ω5-unsaturated anacardic acids in resistant plants are conditioned by a single dominant allele. We propose that inheritance of tall glandular trichome density can be controlled by a small number of loci (possibly as few as one) exhibiting codominance. F2, with low densities of tall glandular trichomes and producing ω5-unsaturated anacardic acids, displayed effective resistance to two-spotted spider mites as measured by mite mortality and fecundity. A genetic model for the biosynthesis of anacardic acids is proposed.


2004 ◽  
Vol 31 (3) ◽  
pp. 267 ◽  
Author(s):  
James L. Smith II ◽  
J. Daniel Hare

Plant trichomes commonly serve a role in mechanical and chemical defence against herbivores, but may also have the potential to alter physiology by reducing the amount of light absorbed by leaves, lowering temperatures, and reducing water loss. Populations of Datura wrightii Regel in southern California produce 'sticky' plants with glandular trichomes and 'velvety' plants bearing non-glandular trichomes. Because stickiness is inherited as a dominant Mendelian trait, and the proportions of sticky plants vary among populations with the moisture availability of their environment, there may be some ecophysiological differences between trichome types that contribute to their ability to survive in a particular geographic location. To examine the possible physiological significance of trichome variation, we measured the spectral properties, midday gas-exchange rates, and water potentials of D. wrightii leaves from sticky and velvety plants growing in a field experiment. The differences in leaf reflectance (0.9%) and absorptance (1.3%) of photosynthetically active radiation (PAR) between trichome types are too small to have any direct physiologically significant effect. Simulations of leaf temperatures based on the difference in leaf absorptances reveal that leaf temperature would be no more than 1°C lower in velvety compared to sticky plants. Gas-exchange measurements revealed no significant difference between types in their transpiration rates or stomatal conductances. In this case, trichome variation may be more important to plant defenses than to physiology.


2018 ◽  
Vol 66 (2) ◽  
pp. 161 ◽  
Author(s):  
Elaine Cotrim Costa ◽  
Renê Gonçalves da Silva Carneiro ◽  
Juliana Santos Silva ◽  
Rosy Mary dos Santos Isaias

Analyses of gall biology and development allow determination of morphogenesis events in host-plant organs that are altered by galling insects. Currently, we assume that there is a correlation between Lopesia sp. instars and the alterations in gall tissues on Mimosa gemmulata that generate the gall shape. The development of Lopesia sp. (three larval instars, pupae and adult) correlates positively with gall growth, especially on the anticlinal axis. First-instar larvae are found in galls at the stage of induction, Instar 2 in galls at early growth and development, Instar 3 in galls at late growth and development, pupae in galls at maturation, and the adult emerges from senescent galls. At induction, the larva stimulates cell differentiation in pinnula and pinna-rachis tissues on M. gemmulata. At early growth and development stages, cell division and expansion are increased, and non-glandular trichomes assist gall closing. Homogenous parenchyma and neoformed vascular bundles characterise late growth and development. At maturation, tissues are compartmentalised and cells achieve major expansion through elongation. At senescence, galls open by the falling of trichomes, and mechanical and nutritive cells have thickened walls. The neoformed nutritive tissue nurtures the developing Lopesia sp., whose feeding behaviour influences the direction of cell elongation, predominantly periclinal, determinant for gall bivalve shape.


Sign in / Sign up

Export Citation Format

Share Document