TDIF overexpression in poplars retards internodal elongation and enhances leaf venation through interaction with other phytohormones

2019 ◽  
Vol 40 (1) ◽  
pp. 60-72 ◽  
Author(s):  
Jing Yue ◽  
Heyu Yang ◽  
Shaohui Yang ◽  
Jiehua Wang
Keyword(s):  
Hybrid Poplar ◽  
Tracheary Element ◽  
Vascular Bundles ◽  
Venation Pattern ◽  
Leaf Venation ◽  
Vein Formation ◽  
Internodal Elongation ◽  
Cle Peptide ◽  
Poplar Leaves

Abstract As a member of the CLAVATA3 (CLV3)/EMBRYO SURROUNDING REGION-related (CLE) peptide family, tracheary element differentiation inhibitory factor (TDIF) plays crucial roles in vascular meristem maintenance by promoting cell proliferation and inhibiting xylem cell differentiation. In Populus trichocarpa, six TDIF-encoding genes are all expressed in vascular tissues, and in Arabidopsis PtTDIFpro:GUS lines, the expression driven by PtTDIF promoters were predominantly detected in stem vascular bundles, initiating leaves and leaf veins. Although exogenous application of two poplar TDIF peptides did not evidently affect the shoot growth in vitro, overexpression of PtTDIF genes in hybrid poplar severely retarded the internodal elongation by upregulating the expression of GA2ox and GA20ox genes and thus decreasing the level of endogenous gibberellins (GAs), which phenotypic defect could be rescued by exogenously applied GA3. In addition, TDIF overexpression unexpectedly induced a more complex venation pattern in poplar leaves, which was underpinned by the elevated expression of WOX4 and WOX13 genes. Upon TDIF treatment, the DR5:GUS poplar leaves revealed a higher GUS activity and in TDIF-overexpressing leaves, the transcript abundances of several PIN-FORMED (PIN) genes, especially that of PIN1, were increased, which implied an integration of TDIF and auxin in mediating this process. Collectively, data of this work presented novel activities of TDIF involved in internode elongation and leaf vein formation, thus revealing the divergent functions of TDIF in perennial tree species from those in annual herbaceous Arabidopsis.

Micro-Structural Stability of Micropropagated Plants of Vitex negundo L.

2021 ◽  
pp. 1-9
Author(s):  
M. Manokari ◽  
S. Priyadharshini ◽  
Mahipal S. Shekhawat
Keyword(s):  
Structural Changes ◽  
Growth Conditions ◽  
Culture Industry ◽  
Vascular Bundles ◽  
Vitex Negundo ◽  
Structural Variations ◽  
Structural Repair ◽  
Micropropagated Plants ◽  
Palisade Cells

Abstract Micropropagation techniques allow producing large numbers of clones of genetically identical plants. However, there is evidence of disorders in internal structures due to sophisticated in vitro conditions. Such variations are responsible for the mortality of plantlets in the field and cause huge loss to the tissue culture industry. Anatomical evaluation at different growth conditions allows for understanding structural repair of in vitro raised plantlets. Therefore, the present study was aimed to identify the structural changes that occurred in micropropagated plants of Vitex negundo under heterotrophic, photomixotrophic, and photoautotrophic conditions. To achieve this, structural variations were analyzed in the plantlets obtained from in vitro, greenhouse and field transferred stages using light microscopy. Underdeveloped dermal tissues, palisade cells, intercellular spaces, mechanical tissues, vascular bundles, and ground tissues were observed with the plants growing under in vitro conditions. The self-repairing of structural disorders and transitions in vegetative anatomy was observed during hardening under the greenhouse environment. Field transferred plantlets were characterized by well-developed internal anatomy. These findings showed that the micropropagated plantlets of V. negundo were well-adapted through a series of self-repairing the in vitro induced structural abnormalities at the subsequent stages of plant development.

Ozone effects on the ultrastructure of the chloroplasts from hybrid poplar leaves

Micron (1969) ◽  
1980 ◽  
Vol 11 (1) ◽  
pp. 13-14 ◽  
Author(s):  
Reginald Noble ◽  
David Pechak ◽  
Keith Jensen
Keyword(s):  
Hybrid Poplar ◽  
Poplar Leaves

The potential digestibility of cellulose in grasses and its relationship with chemical and anatomical parameters

1972 ◽  
Vol 78 (3) ◽  
pp. 457-464 ◽  
Author(s):  
R. J. Wilkins
Keyword(s):  
Floral Development ◽  
Lignin Content ◽  
Leaf Sheath ◽  
Vascular Bundles ◽  
Cellulose Digestibility ◽  
Wimmera Ryegrass ◽  
Rate Of Decline ◽  
The Relationship ◽  
Anatomical Parameters

SUMMARYPotential cellulose digestibility, measured by incubation in vitrofor 6 days, decreased during floral development in perennial ryegrass, Wimmera ryegrass, cocksfoot, oat and tall fescue. The rate of decline was slower than for cellulose digestibility measured after incubation in vitro for 2 days only. Morphological fractions ranked in order of descending potential cellulose digestibility – leaf blade, inflorescence, leaf sheath and stem.Lignin content was determined chemically by the method of Van Soest (1963) and lignified tissue was assessed by staining transverse sections of leaf blades and leaf sheaths with safranin and fast green. Both lignin and lignified tissue increased with maturity. Lignified tissue increased mainly through increase in the number of scleren-chyma cells, but was also affected by the formation of lacunae or cavities between the vascular bundles in leaf blades of cocksfoot and in leaf sheaths of all species studied. For 19 samples of leaf blades and leaf sheaths, potential cellulose digestibility had significant negative correlations with both lignin content (r = -0·862) and lignified tissue (r = -0·905). Limitations to the techniques used to assess lignification and further factors which may affect the relationship between lignification and potential cellulose digestibility are discussed.

Vasoconstriction of outer medullary vasa recta by angiotensin II is modulated by prostaglandin E2

1994 ◽  
Vol 266 (6) ◽  
pp. F850-F857 ◽  
Author(s):  
T. L. Pallone
Keyword(s):  
Angiotensin Ii ◽  
Prostaglandin E2 ◽  
Regional Blood Flow ◽  
Renal Medulla ◽  
Hydraulic Pressure ◽  
Vascular Bundles ◽  
Ang Ii ◽  
Vasa Recta ◽  
Anatomical Arrangement

Vasa recta were dissected from outer medullary vascular bundles in the rat and perfused in vitro. Examination by transmission electron microscopy reveals them to be only outer medullary descending vasa recta (OM-DVR). To establish a method for systematic examination of vasoconstriction, OMDVR were perfused at 5 nl/min with collection pressure increased to 5 mmHg. Under these conditions, transmembrane volume flux was found to be near zero, and the transmural hydraulic pressure gradient was found to be < 15 mmHg. Over a concentration range of 10(-12) to 10(-8) M, abluminal application of angiotensin II (ANG II) caused graded focal vasoconstriction of OMDVR that is blocked by saralasin. Luminal application of ANG II over the same concentration range was much less effective. Abluminal application of prostaglandin E2 (PGE2) shifted the vasoconstrictor response of OMDVR to higher ANG II concentrations. PGE2 reversibly dilated OMDVR that had been preconstricted by ANG II. These results demonstrate that OMDVR are vasoactive segments. Their anatomical arrangement suggests that they play a key role in the regulation of total and regional blood flow to the renal medulla.

scholarly journals Presence of Xylella fastidiosa in Sweet Orange Fruit and Seeds and Its Transmission to Seedlings

2003 ◽  
Vol 93 (8) ◽  
pp. 953-958 ◽  
Author(s):  
W.-B. Li ◽  
W. D. Pria ◽  
P. M. Lacava ◽  
X. Qin ◽  
J. S. Hartung
Keyword(s):  
Vascular System ◽  
Sweet Orange ◽  
Xylella Fastidiosa ◽  
Germination Rate ◽  
Citrus Fruit ◽  
Vascular Bundles ◽  
Specific Amplification ◽  
Root Grafts ◽  
Citrus Seeds

Xylella fastidiosa, a xylem-limited bacterium, causes several economically important diseases in North, Central, and South America. These diseases are transmitted by sharpshooter insects, contaminated budwood, and natural root-grafts. X. fastidiosa extensively colonizes the xylem vessels of susceptible plants. Citrus fruit have a well-developed vascular system, which is continuous with the vascular system of the plant. Citrus seeds develop very prominent vascular bundles, which are attached through ovular and seed bundles to the xylem system of the fruit. Sweet orange (Citrus sinensis) fruit of cvs. Pera, Natal, and Valencia with characteristic symptoms of citrus variegated chlorosis disease were collected for analysis. X. fastidiosa was detected by polymerase chain reaction (PCR) in all main fruit vascular bundles, as well as in the seed and in dissected seed parts. No visual abnormalities were observed in seeds infected with the bacterium. However, the embryos of the infected seeds weighed 25% less than those of healthy seeds, and their germination rate was lower than uninfected seeds. There were about 2,500 cells of X. fastidiosa per infected seed of sweet orange, as quantified using real-time PCR techniques. The identification of X. fastidiosa in the infected seeds was confirmed by cloning and sequencing the specific amplification product, obtained by standard PCR with specific primers. X. fastidiosa was also detected in and recovered from seedlings by isolation in vitro. Our results show that X. fastidiosa can infect and colonize fruit tissues including the seed. We also have shown that X. fastidiosa can be transmitted from seeds to seedlings of sweet orange. To our knowledge, this is the first report of the presence of X. fastidiosa in seeds and its transmission to seedlings.

scholarly journals Adaptability and leaf anatomical features in oil palm seedlings produced by embryo rescue and pre-germinated seeds

2010 ◽  
Vol 22 (3) ◽  
pp. 209-215 ◽  
Author(s):  
Zanderluce G. Luis ◽  
Kadja Milena G. Bezerra ◽  
Jonny Everson Scherwinski-Pereira
Keyword(s):  
Oil Palm ◽  
Embryo Rescue ◽  
Morphological Characteristics ◽  
Growth Conditions ◽  
Epidermal Cells ◽  
In Vitro Cultivation ◽  
Vascular Bundles ◽  
Anatomical Plasticity ◽  
Germinated Seeds

Changes in the leaf structure of plants grown in different conditions have been reported, such as increase in size and density of stomata and reduction in stomatal control, amount of epicuticular wax, and mesophyll thickness, with a high diversity of intercellular spaces. However, these changes are highly variable depending on the physiological and morphological characteristics of each species. The objective of this work was to analyze the adaptability and anatomical plasticity of oil palm seedlings produced after embryo rescue and pre-germinated seeds. Expanded leaves were prepared for evaluation of morphometric data and anatomical structures. It was verified that the environmental conditions in vitro negatively influenced the stomata density, epidermal and hypodermal thickness, and the values for the expansion cells and leaf mesophile. Anatomically, the oil palm leaves present the same tissues composition in both growth conditions, with uniseriate epidermal cells, and tetracitic stomata occurring in both epidermal surfaces. Epidermal cells from in vitro plants are thinner than ones from greenhouse. The midrib of leaves from greenhouse plants are more developed and is composed by only one central vascular bundle, while plants from in vitro cultivation developed three to four collateral vascular bundles.

scholarly journals Influence of salt stress on plants of poplar clone "INRA 353-38" and willow clone "Zhytomyrska-1" in in vitro culture

2020 ◽  
Vol 83 (4) ◽  
pp. 43-49
Author(s):  
Yu. Khoma ◽  
L. Khudolieieva ◽  
N. Kutsokon
Keyword(s):  
Salt Stress ◽  
Sodium Chloride ◽  
In Vitro Culture ◽  
Growth Parameters ◽  
Hybrid Poplar ◽  
Salt Resistance ◽  
Soil Salinization ◽  
In Vitro Cultivation ◽  
Abiotic Factor

Soil salinization is an important abiotic factor negatively affecting plant growth, development and productivity. Fast-growing poplar and willow trees are important plants for bioenergy production demonstrating varying degrees of adaptation to different habitats. The study of salt resistance in different clones of poplars and willows will reveal genotypes that can be planted in saline soils for producing biomass for the bioenergy industry. Therefore, the aim of the study was to investigate the effects of salt stress on poplar plants of clone 'INRA 353-38' (Populus tremula × P. tremuloides) and willow clone 'Zhytomyrska – 1' (Salix sp.) under in vitro culture. For this purpose the plants were cultivated on MS nutrient medium with the addition of sodium chloride in concentrations 25 mM, 50 mM and 100 mM. The control plants were grown on the sodium chloridefree medium. The plant status (with a 4-score scale), the intensity of their growth (by shoot length) and rooting capacity (by the number of roots) were assessed on the 10th and the 30th day of cultivation. The results obtained indicate a high level of sensitivity to sodium chloride of both studied clones under in vitro cultivation. But the willow 'Zhytomyrska – 1' had a higher sensitivity to salt stress comparing to hybrid polar 'ІNRA 353-38' since growth parameters of willow were significantly decreased even under the concentration of sodium chloride 50 mM, and in the case of short term influence (10 days) of the highest concentration of sodium chloride (100 mM) all willow plants terminated their growth and quickly died. The growth parameters of hybrid poplar were declined within a month, mainly under the highest concentration of sodium chloride, but even under such conditions some part of the shoots were able to survive.

In vitro digestibility, breakdown when eaten and physical structure of stovers and straws compared with lucerne hay and sweet potato haulm

1999 ◽  
Vol 132 (4) ◽  
pp. 491-498 ◽  
Author(s):  
D. WILMAN ◽  
YILUN JI ◽  
E. J. MTENGETI ◽  
NAZIR AHMAD
Keyword(s):  
Cell Wall ◽  
Sweet Potato ◽  
Rice Straw ◽  
Physical Structure ◽  
Vascular Bundles ◽  
Milled Material ◽  
Maize Leaves ◽  
Stem Internode ◽  
The Mean

In order to learn more about the digestibility, breakdown when eaten and physical structure of stovers and straws, seven diets were compared in one experiment and eight in another. The diets in the first experiment were: the upper and lower parts of lucerne (Medicago sativa) hay, the leaves, upper stem and lower stem of maize (Zea mays) stover and the leaves and stem of sorghum (Sorghum vulgare) stover. The diets in the second experiment were: the upper and lower parts of lucerne hay, the leaves, stems and whole stover of millet (Setaria italica), wheat (Triticum aestivum) straw, rice (Oryza sativa) straw and sweet potato (Ipomoea batatas) haulm. The diets were examined for in vitro digestibility in three forms: milled, chopped (1 cm lengths) and chewed (by cattle). The lengths and widths of the chewed particles were recorded in both experiments. Aspects of the morphology and vascular structure of plant parts of the diets and of chewed particles were recorded in the second experiment.The in vitro digestibility of chopped or chewed plant material was lower (by 11 and 12 percentage units, respectively, on average) than that of milled material. The difference between chewed and milled material in in vitro digestibility was smaller with leaves (5 percentage units, on average) than with stems (18 percentage units, on average) in maize, sorghum and millet. Digestibility of chewed material was similar to or lower than that of chopped material, except with the leaves of maize, sorghum and millet. Millet stover had higher in vitro digestibility than wheat straw or rice straw, whether the diet was milled, chopped or chewed.The thinnest stem internode vascular bundles recorded (0·14 mm) were in wheat. The percentage of stem internode cross-sectional area occupied by vascular bundles was in the range 6–8 for lucerne, millet, wheat and rice. The mean numbers of veins or vascular bundles per chewed particle were in the range 6–23. The mean length of the chewed particles varied from 10 mm with the upper stem of maize to 18 mm with sorghum stem and maize leaves. The mean width of the chewed particles varied from 1·8 mm with rice straw to 5·4 mm with maize leaves.It is suggested that the low digestibility of mature plant tissue such as stovers and straws is not particularly due to thick vascular strands or to a high proportion of vascular tissue, but rather to a high proportion of cell wall and incomplete and delayed access by rumen microorganisms to much of the cell wall.

scholarly journals Extracellular matrix surface network is associated with non-morphogenic calli of Helianthus tuberosus cv. Albik produced from various explants

2014 ◽  
Vol 83 (1) ◽  
pp. 67-73 ◽  
Author(s):  
Maria Pilarska ◽  
Marzena Popielarska-Konieczna ◽  
Halina Ślesak ◽  
Małgorzata Kozieradzka-Kiszkurno ◽  
Grzegorz Góralski ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
In Vitro Regeneration ◽  
Vascular Bundles ◽  
Helianthus Tuberosus ◽  
Important Species ◽  
Electron Microscopies ◽  
Transmission Electron ◽  
Matrix Surface ◽  
Surface Network

<em>Helianthus tuberosus</em> is economically important species. To improve characters of this energetic plant via genetic modification, production of callus tissue and plant regeneration are the first steps. A new, potentially energetic cultivar Albik was used in this study to test callus induction and regeneration. Callus was produced on leaves, petioles, apical meristems and stems from field-harvested plants but was totally non-morphogenic. Its induction started in the cortex and vascular bundles as confirmed by histological analysis. The surface of heterogeneous callus was partially covered with a membranous extracellular matrix surface network visible in scanning and transmission electron microscopies. The results clearly indicate that: (<strong><em>i</em></strong>) the morphogenic capacity of callus in topinambur is genotype dependent, (<strong><em>ii</em></strong>) cv. Albik of <em>H. tuberosus</em> proved recalcitrant in in vitro regeneration, and (<strong><em>iii</em></strong>) extracellular matrix surface network is not a morphogenic marker in this cultivar.

Histological studies of cellular differentiation during somatic embryogenesis of coconut plumule-derived calli

2015 ◽  
Vol 43 (3) ◽  
Author(s):  
K. Lakshmi Jayaraj ◽  
U. Bhavyashree ◽  
T.P. Fayas ◽  
K.K. Sajini ◽  
M.K. Rajesh ◽  
...  
Keyword(s):  
Somatic Embryogenesis ◽  
Somatic Embryos ◽  
Callus Formation ◽  
Histological Study ◽  
Shoot Meristem ◽  
Vascular Bundles ◽  
Histological Studies ◽  
Meristematic Cells ◽  
Meristem Development

<div><table cellspacing="0" cellpadding="0" align="center"><tbody><tr><td align="left" valign="top"><p>Since coconut is   one of the most recalcitrant species to generate <em>in vitro</em>, it is   necessary to study in detail about the cellular changes that occur during   somatic embryogenesis to enhance our knowledge about this phenomenon. In the   present study, coconut plumular tissues, the shoot meristem including leaf   primordia, were used as explants for <em>in vitro </em>regeneration studies.   Histological studies were carried out in different stages of plumule culture.   No noticeable growth was observed in 15 days old cultures. After 30 days,   meristematic cells could be identified. Abundance of meristematic cells,   foremost to the development of callus structures, was observed after 45 days.   After 75 days, globular friable calli were formed and histological studies   revealed the presence of meristematic centers which eventually formed somatic   embryos. The histological study of matured somatic embryos formed after 120   days of callus initiation showed a clear meristematic zone of parenchyma   cells, surrounded by vascular bundles. Histological studies, carried out for   certain abnormalities like compact calli, abnormal somatic embryoids with   rudimentary shoots and multiplied roots, revealed the presence of intact   cotyledonary leaves which seemed to inhibit the apical meristem development   of somatic embryoids. The presence of vascular bundles in the early stages of   callus formation might lead to the direct formation of meristemoids. These   results could aid future studies leading to enhanced control of the somatic   embryogenic process and greater efficiency of somatic embryo and plantlet   formation in coconut.</p></td></tr></tbody></table></div>

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