Tobacco <i>NtLTP1</i>, a glandular‐specific lipid transfer protein, is required for lipid secretion from glandular trichomes

Choi, Yong Eui,Lim, Soon,Kim, Hyun‐,Jung,Han, Jung Yeon,Lee, Mi‐,Hyun,Yang, Yanyan,Kim, Ji‐,Ah,Kim, Yun‐,Soo Blackwell Publishing Ltd 2012 The Plant journal Vol.70 No.3

<P><B>Summary</B></P><P>Glandular trichomes are the phytochemical factories of plants, and they secrete a wide range of commercially important natural products such as lipids, terpenes and flavonoids. Herein, we report that the <I>Nicotiana tabacum LTP1</I> (<I>NtLTP1</I>) gene, which is specifically expressed in long glandular trichomes, plays a role in lipid secretion from trichome heads. <I>NtLTP1</I> mRNA is abundantly transcribed in trichomes, but <I>NtLTP3</I>, <I>NtLTP4</I> and <I>NtLTP5</I> are not. <I>In situ</I> hybridization revealed that <I>NtLTP1</I> mRNAs accumulate specifically in long trichomes and not in short trichomes or epidermal cells. X‐gluc staining of leaves from a transgenic plant expressing the <I>NtLTP1</I> promoter fused to a <I>GUS</I> gene revealed that NtLTP1 protein accumulated preferentially on the tops of long glandular trichomes. GFP fluorescence from transgenic tobacco plants expressing an NtLTP1‐GFP fusion protein was localized at the periphery of cells and in the excreted liquid droplets from the glandular trichome heads. <I>In vitro</I> assays using a fluorescent 2‐<I>p</I>‐toluidinonaphthalene‐6‐sulfonate probe indicated that recombinant NtLTP1 had lipid‐binding activity. The overexpression of <I>NtLTP1</I> in transgenic tobacco plants resulted in the increased secretion of trichome exudates, including epicuticular wax. In transgenic NtLTP1‐RNAi lines, liquid secretion from trichomes was strongly reduced, but epicuticular wax secretion was not altered. Moreover, transgenic tobacco plants overexpressing <I>NtLTP1</I> showed increased protection against aphids. Taken together, these data suggest that NtLTP1 is abundantly expressed in long glandular trichomes, and may play a role in lipid secretion from long glandular trichomes.</P>

부유부엽성 생이가래 모용의 구조적 특징

지상용,김인선,Ji, Sang-Yong,Kim, In-Sun 한국현미경학회 2002 Applied microscopy Vol.32 No.4

생이가래는 뿌리가 형성되지 않고 부유엽, 침수엽, 줄기로만 구성되어 있는 부유부엽성 수생식물이다. 본 연구는 축소된 생이가래 식물체에 발달하는 세 유형의 모용에 대하여 형태 구조적으로 연구하였다. 부유엽 상피에는 중맥을 중심으로 규칙적으로 배열된 $370{\sim}420{\mu}m$ 크기의 다세포성 모용이 $8{\sim}10$개씩 그룹을 이루며 분포하였다. 반면, 부유엽 하피, 줄기, 포자낭 표면에는 $4{\sim}6$개 세포로 이루어진 $430{\sim}980{\mu}m$의 모용이 발달하였는데, 이때 모용 기저세포의 측면에는 직경 $24{\sim}32{\mu}m$의 반구형의 팽창된 세포가 형성되어 부착하였다. 이와는 달리, 가늘고 길게 세분된 침수엽 표면에는 두 번째 유형과 유사하나 $10{\sim}13$ 또는 그 이상의 세포로 구성된 $2{\sim}2.5mm$ 이상의 매우 긴 모용들이 밀생하여 원주형의 침수엽 표면 전체를 하향으로 둘러싸며 발달하였다. 이들 모용세포에는 발달 초기에 일어난 액포 융합현상으로 세포용적의 대부분을 차지하는 거대 액포가 형성되어 있어 모용세포의 세포질 밀도는 그리 높지 않은 상태를 유지하게 된다. 이와 같이 식물체 전 표피조직에 발달하는 여러 유형의 모용은 조직내부에 형성되어 있는 기실과 함께 축소된 생이가래 식물체의 수중 부유에 중요한 기능을 수행하는 것으로 추정되었다. Salvinia natans, an unique water fern having a small rootless body, developed three different types of trichomes throughout the plant. The most peculiar type exhibiting rows of obvious, whitish, multicellular trichome clusters was noticed in the upper surface of the floating leaves. Eight to ten branches within a cluster extended ca. $370{\sim}420{\mu}m$ from the leaf surface. No stalk cell was found, however, four large epidermal cells were discernable at the base of four central branches in the cluster. Each branch consisted of $8{\sim}10$ obliquely-oriented small cells that gradually decreased in size toward the branch tip. The second type was found in the lower surface of the floating leaves, stems, and sporocarps. Multicellular uniseriate trichomes, ca. $430{\sim}980{\mu}m$ long, were distributed all over these structures. The tip of trichome was acicular, but a semi-spheric protuberance of approximately $24{\sim}32{\mu}m$ in diameter occurred at the base of each trichome. The protuberance appeared to be firmly attached to the side of the basal cell, however, internal connection to the trichome cell itself was uncertain. The third type was similar to the second in that multicellur uniseriate trichomes with acicular tip and a protuberance at the base were present. However, the trichomes were considerably long relative to the second type, and only occurred along the surface of highly dissected, submerged leaves. A majority of the trichomes exceeded more than 2 mm in length that hung downward in the water. Regardless of trichome type, all trichomes contained a huge central vacuole with very thin cytoplasm, resulting from the fusion of several vacuoles during early trichome development. The various densely-distributed trichomes formed in Salvinia natans probably play an important role in plant buoyancy.

Morphological Classification of Trichomes Associated with Possible Biotic Stress Resistance in the Genus Capsicum

김현정,최도일,서은영,김지현,정희진,강병철 한국식물병리학회 2012 Plant Pathology Journal Vol.28 No.1

Trichomes are specialized epidermal structure having the functions of physical and chemical block against biotic and abiotic stresses. Several studies on Capsicum species revealed that virus and herbivore resistance is associated with trichome-formation. However, there is no research on the structural characterization of trichomes developed on the epidermis of Capsicum spp. Thus, this study attempts to charaterize the trichome morphologies in 5 species of Capsicum using a Field Emission Scanning Electron Microscopy (FESEM). Six main trichome types were identified by their morphology under FESEM. Both glandular and non-glandular types of trichomes were developed on the epidermal tissues of Capsicum spp. The glandular trichome were further classified into type I, IV and VII according to their base, stalk length, and stalk. Non-glandular trichomes were also classified into type II, III, and V based on stalk cell number and norphology. Almost all the species in C. chinense and C. pubescens had glandular trichomes. To our knowledge, this is the first study on classification of trichomes in the genus Capsicum and,our results could provide basic informations for understanding the structure and function of trichomes on the epidermal differentiation and association with biotic stress tolerance.

Morphological Classification of Trichomes Associated with Possible Biotic Stress Resistance in the Genus Capsicum

Kim, Hyun-Jung,Seo, Eun-Young,Kim, Ji-Hyun,Cheong, Hee-Jin,Kang, Byoung-Cheorl,Choi, Do-Il The Korean Society of Plant Pathology 2012 Plant Pathology Journal Vol.28 No.1

Trichomes are specialized epidermal structure having the functions of physical and chemical block against biotic and abiotic stresses. Several studies on $Capsicum$ species revealed that virus and herbivore resistance is associated with trichome-formation. However, there is no research on the structural characterization of trichomes developed on the epidermis of $Capsicum$ spp. Thus, this study attempts to charaterize the trichome morphologies in 5 species of $Capsicum$ using a Field Emission Scanning Electron Microscopy (FESEM). Six main trichome types were identified by their morphology under FESEM. Both glandular and non-glandular types of trichomes were developed on the epidermal tissues of $Capsicum$ spp. The glandular trichome were further classified into type I, IV and VII according to their base, stalk length, and stalk. Non-glandular trichomes were also classified into type II, III, and V based on stalk cell number and norphology. Almost all the species in $C.$ $chinense$ and $C.$ $pubescens$ had glandular trichomes. To our knowledge, this is the first study on classification of trichomes in the genus $Capsicum$ and, our results could provide basic informations for understanding the structure and function of trichomes on the epidermal differentiation and association with biotic stress tolerance.

Distribution of Elements on Tobacco Trichomes and Leaves under Cadmium and Sodium Stresses

( Yong Eui Choi ),( Emiko Harada ),( Gwang Hoon Kim ),( Eui Soo Yoon ),( Hiroshi Sano ) 한국식물학회 2004 Journal of Plant Biology Vol.47 No.2

When tobacco (Nicotiana tabacum) plants are exposed to toxic level of cadmium (0.2 mM Cd), their trichomes actively excrete crystals (Choi et al., 2001). In this study, we investigated the distribution of Cd and NaCl on trichomes and leaf surfaces. Energy dispersive x-ray (EDX) analysis revealed that, under toxic Cd stress, crystals exudated from the trichomes contained high amounts of Ca, Mg, and Cd, as well as low levels of P, S, and Mn. Electron spectroscopic imaging (ESI) from trichomes and attached crystals showed that these crystals emitted denser radiation energy for Ca and Cd than did the head cells of the trichomes. However, no Cd was detected on the trichome surface itself or within the leaf epidermis. In contrast, treatment with salt (NaCl) did not stimulate crystal formation; instead, it induced the abnormal expansion of trichome cells. Although Na was not accumulated within the crystals, a consider-able amount of both Na and Cl was sequestered within the stalk cells of the long trichomes. Therefore, we believe that tobacco trichomes play an important role in Cd crystal exudation through crystallization, but that, under NaCl stress, the long trichomes sequester those elements within their stalks.

Characterization of Trichome Morphology and Aphid Resistance in Cultivated and Wild Species of Potato

조광수,강진호,권민,조지홍,임주성,박영은,홍수영,황인택 한국원예학회 2017 Horticulture, Environment, and Biotechnology Vol.58 No.5

Trichomes are specialized epidermal structures that protect plants from abiotic and biotic stresses. Cultivatedpotato (Solanum tuberosum) is known to have both glandular and non-glandular trichomes. However, the criteria fortrichome type classification have not been studied in detail. In addition, there is a poor understanding of the typesof trichomes that exist in wild potato species. Here, the morphology and density of trichomes were compared betweena representative cultivated potato variety and 17 wild potato species using Cryo Scanning Electron Microscopy(CryoSEM). Based on trichome morphology, the cultivated variety and each of the wild species were seen to havetwo glandular and two non-glandular trichome types. We classified the eighteen potato species into four groups usingtrichome type and density criteria. Groups I and II represented species with a higher density of glandular or non-glandulartrichomes, respectively, on both abaxial and adaxial leaf surfaces. Group III represented species with a higher densityof non-glandular trichomes on abaxial leaf surfaces alone. Group IV represented species with an overall lower trichomedensity on both abaxial and adaxial leaf surfaces, but which was formed of both glandular and non-glandular types. Honey dew spots were quantified following infestation with the aphid Macrosiphum euphorbiae to test whether trichomecomposition is associated with resistance to aphid feeding. Fewer honey dew spots were observed in the Group Irepresentative species S. berthaultii and S. hougasii compared to that in species from other groups. Furthermore,correlation coefficient analysis showed that honey dew spot number was negatively associated with glandular trichomedensity. These results imply that glandular trichomes play an important role in aphid resistance and thus can be usedfor developing insect-resistant potato.

Molecular cloning of the tomato <i>Hairless</i> gene implicates actin dynamics in trichome-mediated defense and mechanical properties of stem tissue

Kang, Jin-Ho,Campos, Marcelo L.,Zemelis-Durfee, Starla,Al-Haddad, Jameel M.,Jones, A. Daniel,Telewski, Frank W.,Brandizzi, Federica,Howe, Gregg A. Oxford University Press 2016 Journal of experimental botany Vol.67 No.18

<P>Trichomes are epidermal structures that provide a first line of defense against arthropod herbivores. The recessive <I>hairless</I> (<I>hl</I>) mutation in tomato (<I>Solanum lycopersicum</I> L.) causes severe distortion of trichomes on all aerial tissues, impairs the accumulation of sesquiterpene and polyphenolic compounds in glandular trichomes, and compromises resistance to the specialist herbivore <I>Manduca sexta</I>. Here, we demonstrate that the tomato <I>Hl</I> gene encodes a subunit (SRA1) of the highly conserved WAVE regulatory complex that controls nucleation of actin filaments in a wide range of eukaryotic cells. The tomato <I>SRA1</I> gene spans a 42-kb region containing both <I>Solyc11g013280</I> and <I>Solyc11g013290</I>. The <I>hl</I> mutation corresponds to a complex 3-kb deletion that removes the last exon of the gene. Expression of a wild-type <I>SRA1</I> cDNA in the <I>hl</I> mutant background restored normal trichome development, accumulation of glandular trichome-derived metabolites, and resistance to insect herbivory. These findings establish a role for <I>SRA1</I> in the development of tomato trichomes and also implicate the actin-cytoskeleton network in cytosolic control of specialized metabolism for plant defense. We also show that the brittleness of <I>hl</I> mutant stems is associated with altered mechanical and cell morphological properties of stem tissue, and demonstrate that this defect is directly linked to the mutation in <I>SRA1</I>.</P>

한국산 개미취속 및 근연 분류군의 열매 형태에 관한 분류학적 연구

정규영,정형진 한국자원식물학회 2000 한국자원식물학회지 Vol.13 No.3

광의의 한국산 개미취속의 16종류에 대하여 열매인 수과의 분류학적 가치를 평가하고자 본 연구를 수행하였다. 수과의 형태는 도피침상 장타원형, 도란형, 장타원형, 도란상 장타원형 의 4유형으로 구분되었으며, 수과에 존재하는 모용은 단열성 원추형, 사상형, 원주형, 두상형, 장축 두상형, 구형의 6유형으로 구분되었다. 이들의 수과 선단에서 분포양상은 무모형, 원추상 모용 소생형, 원추상 모용 밀집형, 원추상-두상 모용 혼생형의 4유형으로 구분되었다. 이러한 수과의 형태와 이에 존재하는 모용의 특징은 분류군내의 개체간에는 변이가 없으나 분류군간에는 뚜렷한 차이를 보여 종을 구분하는 좋은 형질로 여겨졌다. 특히 두상형의 모용의 존재여부와 수과선단의 두상형의 모용과 원추형의 모용이 혼생하는 형질은 광의의 Aster속을 Kalimeris, Heteropappus, Aster, Gymnaster속으로 세분할 때, Kalimeris속과 Heteropappus속 및 Aster속의 Pseudocalimeris절을 구분짓는 형질, 즉 절 이상을 구분하는 형질로서 가치를 지니는 것으로 판단되었다. The achene morphology about 16 taxa of Korean Aster L. sensu lato were investigated to estimate its taxonomic values. The achene shapes were divided into four types; oblanceolate-oblong, obovate, oblong and obovate-oblong. The trichome shape on achene six types; uniseriate-conical, filiform, cylindrical, capitate type, long stalk capitate and globular. Their distributional features on upper part of achene four types; absent, sparse distribution of conical trichome, dense distribution of conical trichome and mixed distribution of conical and capitate trichome. The achene shapes and trichome characteristics were regarded to be a good characters in delimiting taxa because these did not differ among individuals in same taxa, but differ among the taxa. If Korean Aster L. sensu late were divided into Kalimeris, Heteropappus, Aster, Cymnaster, the capitate forms and mixed distribution of conical and capitate trichome were recognized as the good characters in delimting above section such as genus Kalimeris and Heteropappus, section Pseudocalimeris of Aster L. sensu stricto.

Ambient Variable Pressure Field Emission Scanning Electron Microscopy for Trichome Profiling of Plectranthus tomentosa by Secondary Electron Imaging

Kim, Ki Woo Korean Society of Microscopy 2013 Applied microscopy Vol.43 No.1

Glandular and nonglandular trichomes on the leaf surface of Plectranthus tomentosa were investigated by variable pressure field emission scanning electron microscopy (VP-FESEM). The segments of the plant's leaves were directly mounted without any specimen preparation, and examined at ambient temperature using a variable pressure secondary electron (SE) detector under ca. 15 Pa. Foliar trichomes maintained their shapes and structures without severe surface collapse or charging. The adaxial leaf surface was abundantly covered with different types of trichome. Nonglandular trichomes consisted of a basal cell and a long (up to ca. $300{\mu}m$) stalk. Meanwhile, capitate glandular trichomes had a secretory head and a short or long stalk. Peltate glandular trichomes with globose secretory heads were observed in close contact with the leaf epidermis. Spherical projections on the secretory head showed the secretion process of glandular trichomes. In addition to the trichomes, oval stomata were distributed on the abaxial leaf surface. These results suggest that ambient VP-FESEM can be used to classify the dehydration-sensitive foliar trichomes of succulent plants by SE imaging. At the FESEM resolution, this approach facilitates the rapid and detailed morphological analysis of a variety of trichomes in diverse plant taxa with reduced labor and preparation.

백리향 (Thymus quinquecostatus Celakovsky) 잎에 분포하는 두상형 분비모의 미세구조

신현철,유성철,Shin, Hyun-Chur,Yu, Seong-Cheol 한국현미경학회 1998 Applied microscopy Vol.28 No.2

The glandular secretory system of the capitate gandular trichomes in leaf of Thymus quinquecostatus Celakovsky was examined by transmission electron microscope. The glandular trichome was consisted of three cell layers; an basal cell layer, a stalk cell with single-celled intermediate layer and a discoid secretory layer with thickened cuticle. The secretory cell was dense, rich in mitochondria, rER, plastds, Golgi complex and had many vesicular structure. Typical plastids with reticulate body and plastoglobule were present in glandular trichome. The tytoplasm of secretory cell was filled with osmiophilic secretory materials. The secretory vesicles, originated from Golgi complex, appeared as membrane bounded vesicles and secreted to the outer wall surface. The presences of well developed rER, mitochondria, Golgi complex, and membrane-bounded vesicles fused with plasmalemma in the secreting cells indicate that the granulocrine mechanism of secretion was occurring in T. quinquecostatus. Subcuticular cavity was developed between the cuticular layer and the secretory cell wall, and it formed above the secretory cell upon separation of cuticle-wall.