Effects of NaCl stress on growth and ion homeostasis in pomegranate tissues

Abstract

Pomegranate is a 'super fruit' that is always adaptable to a saline environment. To elucidate the mechanism underlying the response to salinity, we investigated the effects of NaCl stress on growth and ion balance in six-month-old self-rooted pomegranate cuttings. The plants were fertigated with halfstrength Hoagland's solution containing 0 (control), 100, 200, or 300 mM NaCl every six days. After 18 days, the growth parameter was determined, and dry samples of root, stem and leaf were analyzed for ion content. We found that the growth of pomegranate was not inhibited under 100 mM NaCl stress. With the increased salinity level, excessive accumulations of Na + and Cloccurred in the pomegranate tissues and the net accumulations were ranked as leaf > root > stem. The uptake of K + , Ca 2+ and Mg 2+ was enhanced at low salinity (100 mM) and inhibited at high salinity (300 mM). With increasing salinity, the K + contents in the roots and leaves initially increased and then decreased, with peaks at 200 mM NaCl. The Ca 2+ and Mg 2+ contents increased in the leaves and decreased in the roots. The absorptions of NO 3 and SO 4 2were inhibited by salt stress, but the H 2 PO 4 uptake had no obvious change. The ion ratio and transport coefficient of pomegranate tissues were significantly lower under stress than in controls, but the K + /Na + and Ca 2+ / Na + ratios of the roots and stems were higher than 1 at 100 mM. This study revealed that salinity affected the ion balance in pomegranate tissues through impeding the ion uptake, accumulation and transport. Furthermore, this pomegranate cultivar 'Taishanhong' can adapt to 100 mM NaCl stress by maintaining a stable or higher uptake of K + , Ca 2+ and Mg 2+ to mitigate the detrimental effects of Na + and Clin the cells.

A- Alleviating the harmful impact of salinity stress with different levels by using some organic techniques on vegetative growth characteristics of Wonderful cv. Pomegranate transplants

“…The importance of estimate vegetative growth characteristics which considered the major index to evaluate transplant's salt resistance since they show a normally adaptation with the moderate level and with no obvious injuring symptoms in Tunisi cv. pomegranate was noticed by Liu et al ( 2018) Also, the above-mentioned results are in line with Cuiyu et al (2020) where they proved that plant growth parameters increased with low or moderate salinity levels while increasing salinity stress will cause a reduction in all growth parameters in different pomegranate cultivars.…”

Effective Categorization of Tolerance to Salt Stress through Clustering Prunus Rootstocks According to Their Physiological Performances

“…Usually, this trait can be expressed in terms of biomass or root length. Fruit trees with a degree of tolerance to salinity show a decrease in root biomass (dry weight) at NaCl concentrations as high as 200 and 300 mM as in the case of pomegranate (Punica granatum; L.) [47]. In Vitis vinifera accessions, the root relative growth rate (RGRr) fell between 36% and 40% under 150 mM NaCl [48].…”