Number Of Vessel Elements Research Articles

Role of calcium and magnesium on dramatic physiological and anatomical responses in tomato plants

Minerals are the fundamental source of nutrients for plant functions such as photosynthesis, ATP currency, cellular respiration, metabolic activities, defense mechanisms, and tolerance to biotic and abiotic stressors. Minerals are the most significant component of plant nutrition and applying these minerals supplements can increase fruit output. The study’s main aim was to make agricultural farming easier by foliar applying newly created nutrients like Lebosol-calcium and Magnesium. The four treatments: To (Control), T1 (Lebosol-Mg-Plus, 3 ml/L), T2 (Lebosol-Ca-Forte, 3 ml/L), and T3 (Lebosol-Mg-Plus and Lebosol-Ca-Forte, 3 ml/L) was applied as foliar spray to the seedlings of tomato. It was found that T3 substantially enhanced tomato’s morphological features and yield. The treatment T3 significantly increased total soluble protein, chlorophyll content, and antioxidant enzyme activity. Furthermore, the foliar application of T3 considerably improved phenolic and ascorbic acid contents. The general anatomical features of the leaf, stem, and roots of tomato were qualitatively affected by the treatments. Application of Lebosol-Ca provided the highest total thickness of lamina, number of vessel elements, total phloem area, chlorenchyma layer, total area of vessel elements, xylem ratio, and increased palisade layer thickness, vessel diameter. Furthermore, T3 treatment showed a diverse impact on the internal structure of tomato organs, with palisade and spongy parenchyma growing to maximum values and vessel diameters expanding. T3 had also posed remarkable alterations in morpho-physiological, biochemical, and anatomical aspects in tested plants.

In vitro morphophysiological responses of Alternanthera tenella colla (Amaranthaceae) to stress induced by cadmium and the attenuating action of silicon

Despite having the ability to bioaccumulate trace elements such as cadmium (Cd), many species also present morphophysiological disorders that can hamper their use as phytoremediation plants. Since it can lead to alterations in biomass accumulation, the employment of elements that mitigate stress, such as silicon (Si), can diminish the deleterious effects caused by trace elements. The objective of this study was to analyze the anatomical and physiological modulations induced by the synergy between Cd and Si in Alternanthera tenella Colla plants, as well as to elucidate whether Si can mitigate the harmful effects caused by Cd under in vitro conditions. Nodal segments were cultured in MS medium containing a concentration gradient of Cd (0, 50, 100, or 200 μM) combined with two levels of Si (0 or 40 μM) for a total of eight treatments. After 34 days, the plants' anatomy, physiology, and tolerance index were analyzed. The plants presented anatomical adjustments such as lower stomatal index and number of vessel elements, suggesting lower translocation of Cd to the aerial part. When cultured with 200 μM Cd, the plants presented the lowest Chl a/b ratio (5.55). In the presence of Si, the decline of this ratio was smaller (6.66). Plants exposed to Cd concentrations of 50 μM without Si presented a significant decrease in the performance of the photosynthetic apparatus and tolerance index. The presence of Si in the medium reduced the damages caused by cadmium to the plants' physiology, resulting in greater growth and higher tolerance to this element.

Morphological responses and tolerance of a tree native to the Brazilian Cerrado Astronium fraxinifolium Schott to boron toxicity

The indiscriminate use of fertilizers and chemical pesticides can lead to boron contamination of the soil. Decontamination in general is expensive and results in other impacts. Phytoremediation is a sustainable alternative for soil restoration. Astronium fraxinifolium Schott (Anacardiaceae) is a tree species native to the Cerrado that is considered to be a pioneer species and a selective xerophyte, and it has been widely used in the reforestation and restoration of degraded areas. This study set out to characterize the physiology and anatomy of A. fraxinifolium under different boron concentrations and to assess the tolerance and phytoremediation potential of the species. An experiment with a completely randomized design was conducted in a greenhouse. The carbon allocation and chlorophyll content of leaves of A. fraxinifolium were determined. Boron concentration and the species' tolerance index were calculated from root and shoot samples. Levels of amino acids, proteins, total carbohydrates, starch, phenolic compounds, and anatomical analysis were also measured. A. fraxinifolium showed tolerance to boron concentrations in the substrate and accumulated a greater amount of the element in the aerial part, showing its phytoextraction ability. No significant differences were found in the physiology of A. fraxinifolium; however, some anatomical changes were observed. In the leaves, there were changes in the thickness of the abaxial surface of the epidermis and palisade and spongy parenchyma, and total leaf thickness, and in the roots, there were changes in the thickness of the phloem, diameter of vessel elements, and number of vessel elements per square millimeter. However, boron did not interfere in the development and survival of A. fraxinifolium, which points to the possibility that the species has phytoremediation potential.

Akaline, saline and mixed saline–alkaline stresses induce physiological and morpho‐anatomical changes in Lotus tenuis shoots

Saline, alkaline and mixed saline-alkaline conditions frequently co-occur in soil. In this work, we compared these plant stress sources on the legume Lotus tenuis, regarding their effects on shoot growth and leaf and stem anatomy. In addition, we aimed to gain insight on the plant physiological status of stressed plants. We performed pot experiments with four treatments: control without salt (pH = 5.8; EC = 1.2 dS·m(-1)) and three stress conditions, saline (100 mM NaCl, pH = 5.8; EC = 11.0 dS·m(-1)), alkaline (10 mM NaHCO3, pH = 8.0, EC = 1.9 dS·m(-1)) and mixed salt-alkaline (10 mM NaHCO3 + 100 mM NaCl, pH = 8.0, EC = 11.0 dS·m(-1)). Neutral and alkaline salts produced a similar level of growth inhibition on L. tenuis shoots, whereas their mixture exacerbated their detrimental effects. Our results showed that none of the analysed morpho-anatomical parameters categorically differentiated one stress from the other. However, NaCl- and NaHCO3 -derived stress could be discriminated to different extents and/or directions of changes in some of the anatomical traits. For example, alkalinity led to increased stomatal opening, unlike NaCl-treated plants, where a reduction in stomatal aperture was observed. Similarly, plants from the mixed saline-alkaline treatment characteristically lacked palisade mesophyll in their leaves. The stem cross-section and vessel areas, as well as the number of vascular bundles in the sectioned stem were reduced in all treatments. A rise in the number of vessel elements in the xylem was recorded in NaCl-treated plants, but not in those treated exclusively with NaHCO3.

Variation in Shoot Anatomy and Rooting Behaviour of Stem Cuttings in Relation to Age of Donor Plants in Teak (Tectona grandis Linn. f.)

Shoot anatomical features viz., number of vessel elements, width and length of vessel and fibre elements were studied in relation to juvenility/maturity of teak (Tectona grandis Linn. f.). The findings show significant differences in these features, which indicates that variation in shoot anatomy can be used as a reliable indicator of juvenility/maturity in teak. The effect of age of donor plants and application of auxins on adventitious root formation in single noded leafy stem cuttings of teak was also investigated. Aging of donor trees suppressed rooting and sprouting of cuttings, but increased callus formation at the base of cuttings. Per cent rooting and per cent sprouting in cuttings decreased as age of donor plants increased from 2-months to 15-years and up to 30-years. IBA treatment promoted per cent rooting as well as per cent sprouting, NAA promoted only rooting and it suppressed sprouting. The effect of auxin treatment on rooting and sprouting of teak stem cuttings varied with the age of donor plants. Auxin and its concentration, which suppressed rooting and sprouting in cuttings of younger donor plants, actually promoted rooting when cuttings were taken from more mature donor plants. It appears that the auxin requirement for causing and promoting rooting in teak cuttings increased with increasing age of donor plants. The higher auxin requirement for causing and promoting rooting in cuttings of older trees may be due to a decrease in the content on endogenous auxins or decreased sensitivity of aging tissues to rooting promoters and /or accumulation of inhibitory substances which inhibit rooting.

Vascular Development and Sap Flow in Apple Pedicels

Xylem and phloem tissues of the pedicel of apple fruit increase in cross-sectional area throughout development. The increase in phloem is similar in the two cultivars examined (Cox's Orange Pippin and Royal Gala) and reflects a steadily increasing phloem sap flow to the fruit. The increase in xylem tissue is due to a proliferation of non-conducting, structural, components since close examination reveals no increase in the number of vessel elements from just after flowering onwards. The greater number, and the larger diameter, of the vessels in Cox's explains the initially higher xylem conductance found in this cultivar.In vitro measurements of xylem exudation reveal a decline during the growing season in the xylem conductance of both cultivars and an increasing proportion of fruit (particularly in Cox's) in which the xylem comes to be totally non-conducting. This observation is in line with previously reported measurements of xylem sap flow in vivo.The straightforward techniques used in this study offer a feasible alternative to more arduous methods of assessing xylem and phloem sap flows and their balance during growth.

The Histology of Belladonna Root: Part IV: The differential value of the Fibre/vessel ratio

Summary and Conclusions The term “fibre/vessel ratio” is adopted to signify the number of fibres (including fibre-tracheids exhibiting elongated simple pits) associated with one vessel element. Consistent results are obtained when the fibre/vessel ratio is calculated from the number of vessel elements associated with not less than 200 fibres. The variation in the whole drug of the fibre/vessel ratio and of the vessel index 135μ is investigated and their value as differential characters assessed. Neither character is completely successful in differentiating the whole drug, but some improvement results by combining them in a linear function. A method of determining the fibre/vessel ratio on the powdered drug is described. The fibre/vessel ratio of commercial belladonna root powders decreases with the fineness of the portion examined, but is reasonably constant for the portion retained between a No. 22 and No. 44 sieve. Fibre/vessel ratio values for commercial powders provide a means of differentiating the species from which they were prepared. The ranges for the commercial powders examined are:–A. Belladonna 2°30 to 4°55; A. acuminata 6°54 to 12°05.