Changes in osmotic and ionic indicators in Ananas comosus (L.) cv. MD Gold pre-treated with phytohormones and submitted to saline medium
Maia JM; Lima-Melo Y; Melo YL; Dantas CVS; Macêdo CEC
https://urn.fi/URN:NBN:fi-fe2021042718283
Tiivistelmä
The aim of this study was to evaluate the effect of NaCl on the
hydroponic culture of cv. MD gold pineapple pretreated with the phytohormones
naphthaleneacetic acid (NAA) and 6-benzylaminopurine (BAP) using indicators of
water stress and osmotic adjustment. Pineapple seedlings from saline treatments
in the absence (-NB) and presence (+NB) of the phytohormones during the in
vitro culture were grown in Hoagland & Arnon (1950) nutrient solution in the
absence and presence of different NaCl concentrations (50; 100 and 150 mm) for
10 days in a greenhouse. Plants obtained from in vitro culture pretreated with
phytoregulators (+NB) showed distinct physiological responses compared to
non-treated plants (-NB) in relation to dry mass (DM) in roots, electrolyte
leakage (EL) and Na+ and K+ concentrations in leaves and roots, and also
regarding soluble sugars (TSS), free amino acids (TFAA) and proline (PRO)
concentrations in leaves. Additionally, salt treatments induced similar
responses in -NB and +NB plants, however differing in relation to intensity and
the studied organs. The presence of NaCl in the solution reduced leaf DM in the
-NB treatment, the leaf relative water content in -NB and +NB, and root RWC
only in the -NB treatment. high levels of NaCl increased leaf EL in the +NB
treatment. Potassium levels decreased with the increase of NaCl concentrations
in nutrient solution for leaves and roots submitted to -NB treatment and for
roots submitted to +NB treatment. Leaf potassium levels increased in +NB treatment
regardless of salt treatment. No ionic toxic effects were identified except for
roots subjected to 150 mM NaCl solution both for -NB and +NB conditions. TSS
concentrations decreased with increasing NaCl concentration in leaves for both
-NB and +NB treatments. Furthermore, TFAA and PRO showed increased levels in
leaves subjected to saline stress, being more expressive in -NB treatment. In
conclusion, pretreatment with growth regulators in pineapple plants minimized
the effects of NaCl, despite higher concentrations of this salt affecting most
of the evaluated parameters. Additionally, we conclude that the osmotic effect
of salt stress was determinative for the physiological changes and that roots
have different outcomes regarding the increment of growth regulators and NaCl
concentrations.
Kokoelmat
- Rinnakkaistallenteet [19207]