Influence of Root Zone Calcium on Shoot Tip Necrosis and Apical Dominance of Potato Shoot: Simulation of This Disorder by Ethylene Glycol Tetra Acetic Acid and Prevention by Strontium

Abstract

<jats:p>The important roles of calcium on plant growth and development including cell division and cell elongation is well documented. The purpose of the present study was to determine the impact of root zone calcium on the growth and health of potato apical meristem and on the maintenance of apical dominance. For this purpose, single-node potato cuttings (<jats:italic>Solanum tuberosum</jats:italic> L. cv. Dark Red Norland) were grown in sterilized modified Murashige and Skoog (MS) media containing varying concentrations of calcium (1 to 3000 μM). After 13 to 30 d of growth, plantlets were harvested and data for height of the main shoot and for the number of axillary shoots produced were recorded. Plantlets were ashed and tissue calcium concentration was determined. Shoot height was retarded with decreasing concentration of calcium in the media. Calcium deficiency induced shoot tip injury and loss of apical dominance. Tip injury was followed by the development of axillary shoots. The number of axillary shoots increased from one to 21 as calcium concentration in the media decreased from 3000 to 1 μM. At calcium concentration of 1500 μM or higher, there was a single main shoot with no axillary shoots. Addition of ethylene glycol tetra acetic acid (EGTA), a calcium chelator, to the media with 2720 μM calcium (sufficient calcium) resulted in the development of shoot injury and in the formation of axillary shoots. Calcium deficiency injury symptoms were prevented by the addition of a calcium analog, strontium, to MS media deficient in calcium. Strontium has been reported to strongly bind to plant cell walls and the inclusion of strontium prevented injury in shoots of plants grown on calcium-deficient media. These results suggest that strontium is able to mimic the role of calcium in the maintenance of cell wall integrity and supports previous studies that showed that calcium deficiency results from cell wall collapse of the subapical cells.</jats:p>

CAX1 Vacuolar Antiporter Overexpression in Potato Results in Calcium Deficiency in Leaves and Tubers by Sequestering Calcium as Calcium Oxalate

“…It is also known that Ca 2+ deficiency in many plants, including potatoes, can cause shoot tip injury that leads to tip necrosis and death of the main shoot (Sha et al, 1985, Busse et al, 2008Ozgen et al, 2011). This shoot tip injury has been shown to result from collapse of expanding subapical cell walls due to lack of Ca 2+ (Busse et al, 2008).…”

Element accumulation capacity of Vaccinium myrtillus from Montenegro: Comparison of element contents in water and ethanol extracts of bilberry plant parts

“…Therefore, Sr was easily absorbed by bilberry. Although it is known that Sr is not essential for the growth and multiplication of most plants, it is necessary for the metabolic demands of Ca in plants [27].…”

Shoot tip necrosis of in vitro plant cultures: a reappraisal of possible causes and solutions

“…was increased from 1 µM to 3000 µM, number of axillary shoots decreased from 21 to 1. STN increased when 5 mM EGTA was added to SMM, but decreased when 204 µM strontium was added Ozgen et al ( 2011 ) Solanum tuberosum L. cv. Burbank, Dark Red Norland, Atlantic, Superior, Snowden Same as Ahmed and Palta ( 2017a ).…”

“…The level of CaCl 2 was one of the factors that affected the level of STN in Indian lilac ( Azadirachta indica A. Juss) cultures (Arora et al 2010 ). In potato ‘Dark Red Norland’, Ozgen et al ( 2011 ) ascribed the increase in STN, as a result of low Ca 2+ levels in medium, to injury of the shoot tip and subsequent loss of apical dominance, thereby stimulating axillary shoot formation. In Indian redwood ( Soymida febrifuga (Roxb.)…”

“…Therefore, it is inconclusive to attribute the problem of STN exclusively to Ca 2+ deficiency while the role of Cl − is completely overlooked. Numerous examples of this inconclusiveness can be found in the literature (Barghchi and Alderson 1996 ; Piagnani et al 1996 ; Bairu et al 2009a , 2009b ; Ozgen et al 2011 ; Machado et al 2014 ; Poothong and Reed 2014 ; Surakshitha et al 2019 ). Nevertheless, it has recently been proved that Cl − (> 4.67 mM) has a positive effect on reducing STN symptoms in pistachio (Nezami-Alanagh et al 2019 ).…”