Influence of Ca2+ and 6-benzyladenine on chestnut (Castanea sativa Mill.) in vitro shoot-tip necrosis

Background and Aim: Hydrolyzable tannins are an important group of secondary plant metabolites, which are known for antimicrobial activity. This study aimed to assess the efficiency with which a hydrolyzable tannin extract from sweet chestnut wood (Castanea sativa Mill.) could inhibit mastitis-causing bacteria in vitro. Materials and Methods: The negative control used was sterile water, and the positive controls were penicillin and gentamicin. The treatments included five concentrations of hydrolyzable tannins (63, 190, 313, 630, and 940 mg/mL). In cows with subclinical mastitis, the bacteria causing the disease were isolated and identified. Then, the antibacterial activity of the hydrolyzable tannin extract was assessed by the disk diffusion method, by determining the minimum inhibitory concentration (MIC) and by determining the minimum bactericidal concentration (MBC). Results: Penicillin inhibited (p<0.01) the growth of Staphylococcus aureus, Streptococcus uberis, and Pseudomonas aeruginosa but could not inhibit (p>0.05) the growth of Streptococcus agalactiae, Escherichia coli, and Klebsiella pneumoniae. However, gentamicin and hydrolyzable tannins could inhibit (p<0.01) all isolated bacteria. Increasing the concentration of hydrolyzable tannin extract resulted in a quadratic increase in the inhibition zone diameter of S. aureus and S. agalactiae and a linear increase in the inhibition zone diameter of E. coli, K. pneumoniae, and P. aeruginosa. In addition, 630 and 940 mg/mL of hydrolyzable tannin extract showed the highest antibacterial activity against S. agalactiae and E. coli (p<0.01), while 940 mg/mL concentration had the highest antibacterial activity against K. pneumoniae (p<0.01). The MIC and MBC of the extract were 27.3-190 mg/mL and 58.8-235 mg/mL, respectively, with the MBC: MIC ratio being 2:1. Conclusion: The antimicrobial activity of the hydrolyzable tannin extract against subclinical mastitis bacteria was comparable to the antibiotics (positive controls) at concentrations over 630 mg/mL. Although these in vitro findings are promising, further research is needed to determine whether hydrolyzable tannins could be used to control or prevent subclinical mastitis in dairy cows.

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In vitro culture of cotyledon tissue of Castanea sativa Mill

Scientia Horticulturae ◽

10.1016/0304-4238(78)90031-6 ◽

1978 ◽

Vol 8 (3) ◽

pp. 243-247 ◽

Cited By ~ 6

Author(s):

A.M. Vieitez ◽

M.L. Gonzalez ◽

E. Vieitez

Keyword(s):

In Vitro Culture ◽

Castanea Sativa ◽

Castanea Sativa Mill

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Boron on in vitro growth and enzymatic activity of Blueberry

Revista Brasileira de Fruticultura ◽

10.1590/0100-29452021478 ◽

2021 ◽

Vol 43 (5) ◽

Author(s):

Jessé Neves dos Santos ◽

Ricardo Antonio Ayub ◽

Isabela Letícia Pessenti ◽

André Belmont Pereira

Keyword(s):

Enzymatic Activity ◽

Boric Acid ◽

High Activity ◽

Shoot Tip ◽

In Vitro Growth ◽

The Third ◽

Shoot Tip Necrosis

Abstract Boron (B) is essential for plants metabolism and most culture mediums use the same concentration, but in different quantities this nutrient may provoke growth alterations. Thus, the purpose of this study was to examine the effect of B on in vitro growth of blueberry in three experiments. The first experiment of multiplication (evaluated at 90 days) used 3 concentrations of 2-isopentenyladenine-2iP with 4 concentrations of boric acid-BA (factorial scheme 3x4). The second used 4 concentrations of BA and 1 concentration of 2iP and the third (rooting) used 4 concentrations of BA and 1 concentration of indolbutyric acid-IBA both evaluated at 180 days (unifactorial scheme). All the experiments had 4 replicates with explants. 6.2 mg L-1 of B and 5.0 mg L-1 of 2iP generated the highest shoot quantity (18.4, 25.5 respectively). From the interaction of these concentrations, there was the highest activity of POD and PPO enzymes. Under B deficit was seen a larger number of shoot-tip necrosis (9), red leaves (31) and high activity of the PAL, IAAO and POD enzymes. With IBA the correlation between IAAO and the roots’ growth was positive, showing that blueberry rooting depends of both B and IAAO regulation.

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Influence of Root Zone Calcium on Subapical Necrosis in Potato Shoot Cultures: Localization of Injury at the Tissue and Cellular Levels

Journal of the American Society for Horticultural Science ◽

10.21273/jashs.133.5.653 ◽

2008 ◽

Vol 133 (5) ◽

pp. 653-662 ◽

Cited By ~ 9

Author(s):

James S. Busse ◽

Senay Ozgen ◽

Jiwan P. Palta

Keyword(s):

Shoot Apical Meristem ◽

Apical Dominance ◽

Apical Meristem ◽

Calcium Deficiency ◽

Shoot Tip ◽

Axillary Shoot ◽

Shoot Cultures ◽

Primary Injury ◽

Shoot Tip Necrosis

Shoot tip necrosis has been attributed to calcium deficiency in in vitro cultures, resulting in death of the stem tip, the loss of apical dominance, and axillary branch development. Using an in vitro shoot culture system with Solanum tuberosum L. cv. Dark Red Norland, we studied the development of injury symptoms at the microscopic and tissue levels at a range of media calcium concentrations varying from 6.8 to 3000 μm. Light and electron microscopic studies revealed that the primary injury due to calcium deficiency was the death and collapse of expanding pith cells below the shoot apex. The structure and organization of the shoot apical meristem was the same when plants were cultured on sufficient or suboptimal media calcium concentrations. However, the apical meristem senesced following subapical shoot tissue collapse. Death of the shoot apical meristem was a secondary effect of calcium deficiency, resulting in loss of apical dominance. Studies with 45Ca indicated that calcium was distributed in a gradient along the shoot, with highest concentration at the base and the lowest at the apex. Shoot tip necrosis developed after 20 days of culture on the suboptimal calcium concentration medium. The development of these symptoms and axillary shoot growth was associated with the lack of calcium accumulation in the shoots. Our results provide evidence that a primary injury of calcium deficiency is localized in the expanding pith cells below the shoot apical meristem and this injury results in the collapse of subapical cells. Death of the shoot apical meristem is a secondary injury resulting from calcium deficiency.

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