Physico-chemical changes in karkade (Hibiscus sabdariffa L.) seedlings responding to salt stress.
Salinity is one of the major abiotic stress factors affecting series of morphological, physiological, metabolic and molecular changes in plant growth. The effect of different concentrations (0, 25, 50, 100 and 150 mM) of NaCl on the vegetative growth and some physiological parameters of karkade (Hibiscus sabdariffa var. sabdariffa) seedling were investigated. NaCl affected the germination rate, delayed emergence and retarded vegetative growth of seedlings. The length of seedling as well as the leaf area was significantly reduced. The fresh weight remained lower in NaCl treated seedlings compared to control. NaCl at 100 and 150 mM concentrations had significant effect on the dry matter contents of the treated seedlings. The chloroplast pigments in the treated seedlings were affected, suggesting that the NaCl had a significant effect on the chlorophyll and carotenoid biosynthesis. The results showed that the salt treatments induced an increase in proline concentration of the seedlings. The osmotic potential (ψs) of NaCl treated seedlings decreased with increasing NaCl concentrations. Salt treatments resulted in dramatic quantitative reduction in the total sterol percent compared with control ones. Salt stress resulted in increase and decrease of Na+and K+ions, respectively. NaCl salinity increased lipid peroxidation. SDS-PAGE was used to evaluate protein pattern after applying salt stress. High molecular weight proteins were intensified, while low molecular weight proteins were faint. NaCl at 100 and 150 mM concentration distinguished with new protein bands. Salt stress induced a new peroxidase bands and increased the band intensity, indicating the protective role of peroxidase enzyme.
Botany Department, Faculty of Science, Sohag University , 82524 Sohag , Egypt.
Abdelnasser
A
Galal
D002338:Carotenoids / Q000096:biosynthesis; D055598:Chemical Phenomena; D002734:Chlorophyll / Q000096:biosynthesis; D004305:Dose-Response Relationship, Drug; D004591:Electrophoresis, Polyacrylamide Gel; D018525:Germination / Q000187:drug effects; D031584:Hibiscus / Q000737:chemistry / Q000187:drug effects* / Q000502:physiology; D015227:Lipid Peroxidation / Q000187:drug effects; D008315:Malondialdehyde / Q000378:metabolism; D009997:Osmotic Pressure / Q000187:drug effects; D009195:Peroxidase / Q000378:metabolism; D018515:Plant Leaves / Q000187:drug effects / Q000502:physiology; D010940:Plant Proteins / Q000378:metabolism; D011188:Potassium / Q000378:metabolism; D011392:Proline / Q000378:metabolism; D054712:Salinity; D036226:Seedlings / Q000737:chemistry / Q000187:drug effects* / Q000502:physiology; D012639:Seeds / Q000187:drug effects / Q000502:physiology; D012964:Sodium / Q000378:metabolism; D012965:Sodium Chloride / Q000494:pharmacology*
D010940:Plant Proteins; D002734:Chlorophyll; D002338:Carotenoids; D012965:Sodium Chloride; D008315:Malondialdehyde; D011392:Proline; D012964:Sodium; D009195:Peroxidase; D011188:Potassium
Carotenoids; chlorophyll; karkade; peroxidase; pigments; salt stress; seedling emergence