Trichome micromorphology of the Chinese-Himalayan genus Colquhounia (Lamiaceae), with emphasis on taxonomic implications

Biologia ◽  
2012 ◽  
Vol 67 (5) ◽  
Author(s):  
Guo-Xiong Hu ◽  
Teodora Balangcod ◽  
Chun-Lei Xiang

AbstractTrichome micromorphology of leaves and young stems of nine taxa (including four varieties) of Colquhounia were examined using light and scanning microscopy. Two basic types of trichomes were recognized: eglandular and glandular. Eglandular trichomes are subdivided into simple and branched trichomes. Based on the number of cells and trichome configuration, simple eglandular trichomes are further divided into four forms: unicellular, two-celled, three-celled and more than three-celled trichomes. Based on branching configuration, the branched eglandular trichomes can be separated into three forms: biramous, stellate and dendroid. Glandular trichomes can be divided into two subtypes: capitate and peltate glandular trichomes. Results from this study of morphological diversity of trichomes within Colquhounia lend insight into infrageneric classification and species relationships. Based on the presence of branched trichomes in C. elegans, this species should be transferred from Colquhounia sect. Simplicipili to sect. Colquhounia. We provide a taxonomic key to species of Chinese Colquhounia based on trichome morphology and other important morphological traits.

2021 ◽  
Vol 8 (3) ◽  
Author(s):  
E Sanoj ◽  
P Deepa

Ocimum L. is an attractive fragrant ornamental plant with medicinal aromatic compounds. The study using digital microscopy revealed the distinct epidermal trichome morphology in five species of Ocimum including O. americanum L., O. basilicum L., O. gratissimum L., O. kilimandscharicum Gurke and O. tenuiflorum L. A distinguished variation in size, shape, type and abundance of trichomes on leaves and stem of all species are described and photographed. Both glandular and non-glandular trichomes scrutinized in all the species in which glandular type comprised capitate and peltate trichomes. On the stem, the longest glandular capitate trichome (GCT) and non-glandular trichome (NGT) were observed in O. tenuiflorum while O. basilicum possessed longest glandular peltate trichome (GPT). In case of foliar trichomes, the longest GCT observed on leaves of O. americanum; and O. basilicum showed the longest GPT and NGT. In the species, the septate or aseptate NGT possessed uni, bi or multicellular base with acute or broad apex. A distinguished variation in the number of cells in stalk and head of GT was observed in the study. Presence of silica bodies in peltate trichome of O. kilimandscharicum was noticed as the characteristic feature. Among the five species, the trichomes were abundant in O. kilimandscharicum; while O. basilicum showed sparse distribution. Trichomes with disrupted cells were also noted in O. americanum. Due to the presence of specific trichome characteristics, the efficient taxonomic key is prepared to identify the taxa at species level.


Phytotaxa ◽  
2013 ◽  
Vol 119 (1) ◽  
pp. 1 ◽  
Author(s):  
JULIANA SANTOS-SILVA ◽  
ANA MARIA GOULART DE AZEVEDO TOZZI ◽  
MARCELO FRAGOMENI SIMON ◽  
NAZARETH GUEDES URQUIZA ◽  
MATÍAS MORALES

With more than 500 species, Mimosa L. is one of the largest genera of the Leguminosae. It exhibits considerable trichome diversity among species. Trichome types have been used as diagnostic characters, but some are not well known and have been poorly described in taxonomic works, causing some difficulties for species identification and description. The morphology of trichomes of 35 species was studied using scanning electron microscopy and light microscopy to define the types of trichomes precisely. An ancestral character state reconstruction using a densely-sampled phylogeny of the genus was performed in order to investigate the evolution of trichome types in Mimosa. Two basic types of trichomes can be distinguished: glandular and non-glandular. The glandular trichomes can be sessile or stalked. The non-glandular trichomes can be unbranched or branched. Unbranched trichomes are unicellular and conical or cylindrical, whereas branched trichomes are multicellular and verruciform, medusiform, plumose, barbellate, stellate, stellate-lepidote, or lepidote. Character optimization analysis suggests that glandular and branched trichomes are derived and evolved independently in different lineages within Mimosa. The ancestral condition in Mimosa was probably non-glandular and unbranched trichomes, which was retained from piptadenioid ancestors. Our study provides a first insight into the evolutionary history of trichome morphology in the genus. Despite high levels of homoplasy, trichome morphology offers a set of characters that can be used for differentiating species and species groups in combination with other characters. 


Planta ◽  
2021 ◽  
Vol 254 (1) ◽  
Author(s):  
Rodrigo Therezan ◽  
Ruy Kortbeek ◽  
Eloisa Vendemiatti ◽  
Saioa Legarrea ◽  
Severino M. de Alencar ◽  
...  

Abstract Main conclusion Cultivated tomatoes harboring the plastid-derived sesquiterpenes from S. habrochaites have altered type-VI trichome morphology and unveil additional genetic components necessary for piercing-sucking pest resistance. Abstract Arthropod resistance in the tomato wild relative Solanum habrochaites LA1777 is linked to specific sesquiterpene biosynthesis. The Sesquiterpene synthase 2 (SsT2) gene cluster on LA1777 chromosome 8 controls plastid-derived sesquiterpene synthesis. The main genes at SsT2 are Z-prenyltransferase (zFPS) and Santalene and Bergamotene Synthase (SBS), which produce α-santalene, β-bergamotene, and α-bergamotene in LA1777 round-shaped type-VI glandular trichomes. Cultivated tomatoes have mushroom-shaped type-VI trichomes with much smaller glands that contain low levels of monoterpenes and cytosolic-derived sesquiterpenes, not presenting the same pest resistance as in LA1777. We successfully transferred zFPS and SBS from LA1777 to cultivated tomato (cv. Micro-Tom, MT) by a backcrossing approach. The trichomes of the MT-Sst2 introgressed line produced high levels of the plastid-derived sesquiterpenes. The type-VI trichome internal storage-cavity size increased in MT-Sst2, probably as an effect of the increased amount of sesquiterpenes, although it was not enough to mimic the round-shaped LA1777 trichomes. The presence of high amounts of plastid-derived sesquiterpenes was also not sufficient to confer resistance to various tomato piercing-sucking pests, indicating that the effect of the sesquiterpenes found in the wild S. habrochaites can be insect specific. Our results provide for a better understanding of the morphology of S. habrochaites type-VI trichomes and paves the way to obtain insect-resistant tomatoes.


2021 ◽  
Author(s):  
Matthew J Gadenne ◽  
Iris Hardege ◽  
Djordji Suleski ◽  
Paris Jaggers ◽  
Isabel Beets ◽  
...  

Sexual dimorphism occurs where different sexes of the same species display differences in characteristics not limited to reproduction. For the nematode Caenorhabditis elegans, in which the complete neuroanatomy has been solved for both hermaphrodites and males, sexually dimorphic features have been observed both in terms of the number of neurons and in synaptic connectivity. In addition, male behaviours, such as food-leaving to prioritise searching for mates, have been attributed to neuropeptides released from sex-shared or sex-specific neurons. In this study, we show that the lury-1 neuropeptide gene shows a sexually dimorphic expression pattern; being expressed in pharyngeal neurons in both sexes but displaying additional expression in tail neurons only in the male. We also show that lury-1 mutant animals show sex differences in feeding behaviours, with pharyngeal pumping elevated in hermaphrodites but reduced in males. LURY-1 also modulates male mating efficiency, influencing motor events during contact with a hermaphrodite. Our findings indicate sex-specific roles of this peptide in feeding and reproduction in C. elegans, providing further insight into neuromodulatory control of sexually dimorphic behaviours.


Genetics ◽  
2021 ◽  
Author(s):  
Hana E Littleford ◽  
Karin Kiontke ◽  
David H A Fitch ◽  
Iva Greenwald

Abstract Specialized cells of the somatic gonad primordium of nematodes play important roles in the final form and function of the mature gonad. C. elegans hermaphrodites are somatic females that have a two-armed, U-shaped gonad that connects to the vulva at the midbody. The outgrowth of each gonad arm from the somatic gonad primordium is led by two female Distal Tip Cells (fDTC), while the Anchor Cell (AC) remains stationary and central to coordinate uterine and vulval development. The bHLH protein HLH-2 and its dimerization partners LIN-32 and HLH-12 had previously been shown to be required for fDTC specification. Here, we show that ectopic expression of both HLH-12 and LIN-32 in cells with AC potential transiently transforms them into fDTC-like cells. Furthermore, hlh-12 was known to be required for the fDTCs to sustain gonad arm outgrowth. Here, we show that ectopic expression of HLH-12 in the normally stationary AC causes displacement from its normal position, and that displacement likely results from activation of the leader program of fDTCs because it requires genes necessary for gonad arm outgrowth. Thus, HLH-12 is both necessary and sufficient to promote gonadal regulatory cell migration. As differences in female gonadal morphology of different nematode species reflect differences in the fate or migratory properties of the fDTCs or of the AC, we hypothesized that evolutionary changes in the expression of hlh-12 may underlie evolution of such morphological diversity. However, we were unable to identify an hlh-12 ortholog outside of Caenorhabditis. Instead, by performing a comprehensive phylogenetic analysis of all Class II bHLH proteins in multiple nematode species, we found that HLH-12 evolved within the Caenorhabditis clade, possibly by duplicative transposition of hlh-10. Our analysis suggests that control of gene regulatory hierarchies for gonadogenesis can be remarkably plastic during evolution without adverse phenotypic consequence.


2020 ◽  
Author(s):  
Carina C. Kern ◽  
StJohn Townsend ◽  
Antoine Salzmann ◽  
Nigel B. Rendell ◽  
Graham W. Taylor ◽  
...  

AbstractAdult C. elegans hermaphrodites exhibit severe senescent pathology that begins to develop within days of reaching sexual maturity (Ezcurra et al., 2018; Garigan et al., 2002; Herndon et al., 2002; Wang et al., 2018). For example, after depletion of self-sperm, intestinal biomass is converted into yolk leading to intestinal atrophy and yolk steatosis (pseudocoelomic lipoprotein pools, PLPs) (Ezcurra et al., 2018; Garigan et al., 2002; Herndon et al., 2002; Sornda et al., 2019). These senescent pathologies are promoted by insulin/IGF-1 signalling (IIS), which also shortens lifespan (Ezcurra et al., 2018; Kenyon, 2010). This pattern of rapid and severe pathology in organs linked to reproduction is reminiscent of semelparous organisms where massive reproductive effort leads to rapid death (reproductive death) as in Pacific salmon (Finch, 1990; Gems et al., 2020). Moreover, destructive conversion of somatic biomass to support reproduction is a hallmark of reproductive death (Gems et al., 2020). Yet arguing against the occurrence of reproductive death in C. elegans is the apparent futility of post-reproductive yolk production. Here we show that this effort is not futile, since post-reproductive mothers vent yolk through their vulva, which is consumed by progeny and supports their growth; thus vented yolk functions as a milk, and C. elegans mothers exhibit a form of lactation. Moreover, IIS promotes lactation, thereby effecting a costly process of resource transfer from postreproductive mothers to offspring. These results support the view that C. elegans hermaphrodites exhibit reproductive death involving a self-destructive process of lactation that is promoted by IIS. They also provide new insight into how the strongly life-shortening effects of IIS in C. elegans evolved.


Molecules ◽  
2022 ◽  
Vol 27 (1) ◽  
pp. 312
Author(s):  
Tina V. A. Hansen ◽  
Heinz Sager ◽  
Céline E. Toutain ◽  
Elise Courtot ◽  
Cédric Neveu ◽  
...  

Natural plant compounds, such as betaine, are described to have nematocidal properties. Betaine also acts as a neurotransmitter in the free-living model nematode Caenorhabditis elegans, where it is required for normal motility. Worm motility is mediated by nicotinic acetylcholine receptors (nAChRs), including subunits from the nematode-specific DEG-3 group. Not all types of nAChRs in this group are associated with motility, and one of these is the DEG-3/DES-2 channel from C. elegans, which is involved in nociception and possibly chemotaxis. Interestingly, the activity of DEG-3/DES-2 channel from the parasitic nematode of ruminants, Haemonchus contortus, is modulated by monepantel and its sulfone metabolite, which belong to the amino-acetonitrile derivative anthelmintic drug class. Here, our aim was to advance the pharmacological knowledge of the DEG-3/DES-2 channel from C. elegans by functionally expressing the DEG-3/DES-2 channel in Xenopus laevis oocytes and using two-electrode voltage-clamp electrophysiology. We found that the DEG-3/DES-2 channel was more sensitive to betaine than ACh and choline, but insensitive to monepantel and monepantel sulfone when used as direct agonists and as allosteric modulators in co-application with betaine. These findings provide important insight into the pharmacology of DEG-3/DES-2 from C. elegans and highlight the pharmacological differences between non-parasitic and parasitic nematode species.


2020 ◽  
Author(s):  
Sierra Rosiana ◽  
Liyang Zhang ◽  
Grace H. Kim ◽  
Alexey V. Revtovich ◽  
Arjun Sukumaran ◽  
...  

AbstractCandida albicans is a microbial fungus that exists as a commensal member of the human microbiome and an opportunistic pathogen. Cell surface-associated adhesin proteins play a crucial role in C. albicans’ ability to undergo cellular morphogenesis, develop robust biofilms, colonize, and cause infection in a host. However, a comprehensive analysis of the role and relationships between these adhesins has not been explored. We previously established a CRISPR-based platform for efficient generation of single- and double-gene deletions in C. albicans, which was used to construct a library of 144 mutants, comprising 12 unique adhesin genes deleted singly, or in every possible combination of double deletions. Here, we exploit this adhesin mutant library to explore the role of adhesin proteins in C. albicans virulence. We perform a comprehensive, high-throughput screen of this library, using Caenorhabditis elegans as a simplified model host system, which identified mutants critical for virulence and significant genetic interactions. We perform follow-up analysis to assess the ability of high- and low-virulence strains to undergo cellular morphogenesis and form biofilms in vitro, as well as to colonize the C. elegans host. We further perform genetic interaction analysis to identify novel significant negative genetic interactions between adhesin mutants, whereby combinatorial perturbation of these genes significantly impairs virulence, more than expected based on virulence of the single mutant constituent strains. Together, this yields important new insight into the role of adhesins, singly and in combinations, in mediating diverse facets of virulence of this critical fungal pathogen.SummaryCandida albicans is a human fungal pathogen and cause of life-threatening systemic infections. Cell surface-associated adhesins play a central role in this pathogen’s ability to establish infection. Here, we provide a comprehensive analysis of adhesin factors, and their role in fungal virulence. Exploiting a high-throughput workflow, we screened an adhesin mutant library using C. elegans as a simple model host, and identified mutants and genetic interactions involved in virulence. We found that adhesin mutants are impaired in in vitro pathogenicity, irrespective of their virulence. Together, this work provides new insight into the role of adhesin factors in mediating fungal virulence.


2018 ◽  
Vol 23 (1) ◽  
pp. 56
Author(s):  
Djoko Santosa ◽  
Subagus Wahyuono ◽  
Sugeng Riyanto ◽  
SM Widyastuti

A morphological diversity analysis of Scoparia dulcis by macroscopy and microscopy has been conducted. The aim of this research is to determine the morphological and anatomical character of S. dulcis which grow in Opak watershed, Special Region of Yogyakarta. Samples were taken from Sleman (Cangkringan, Ngemplak Kalasan, and Prambanan) and Bantul (Imogiri and Pundong) region. Selection of sampling location is based on altitude difference. The samples are the third leaf order from the tip of the stem. They were measured in length and width. Microscopy analysis was performed by observing the number of glandular trichomes, palisade cells in the epidermis and stomata in the upper and lower epidermis. The data obtained were analyzed using principal component analysis (PCA). The results show that based on morphological and anatomical assessment, there were found 3 clusters of S. dulcis, i.e. Cangkringan-Ngemplak-Prambanan, Kalasan, and Imogiri-Pundong cluster.


2021 ◽  
Vol 14 ◽  
Author(s):  
Umer Saleem Bhat ◽  
Navneet Shahi ◽  
Siju Surendran ◽  
Kavita Babu

One of the reasons that most multicellular animals survive and thrive is because of the adaptable and plastic nature of their nervous systems. For an organism to survive, it is essential for the animal to respond and adapt to environmental changes. This is achieved by sensing external cues and translating them into behaviors through changes in synaptic activity. The nervous system plays a crucial role in constantly evaluating environmental cues and allowing for behavioral plasticity in the organism. Multiple neurotransmitters and neuropeptides have been implicated as key players for integrating sensory information to produce the desired output. Because of its simple nervous system and well-established neuronal connectome, C. elegans acts as an excellent model to understand the mechanisms underlying behavioral plasticity. Here, we critically review how neuropeptides modulate a wide range of behaviors by allowing for changes in neuronal and synaptic signaling. This review will have a specific focus on feeding, mating, sleep, addiction, learning and locomotory behaviors in C. elegans. With a view to understand evolutionary relationships, we explore the functions and associated pathophysiology of C. elegans neuropeptides that are conserved across different phyla. Further, we discuss the mechanisms of neuropeptidergic signaling and how these signals are regulated in different behaviors. Finally, we attempt to provide insight into developing potential therapeutics for neuropeptide-related disorders.


Sign in / Sign up

Export Citation Format

Share Document