S Nutrition Is Involved in Alleviation of Damage of Photosynthetic Organelles by Salt Stress in Kentucky Bluegrass (\u3cem\u3ePoa pratensis\u3c/em\u3e L.)
Salt-stress is considered as one of the major environmental factor limiting plant growth and productivity. It has been well reported that salt stress induce the reduction of stomatal density and number leading to poor gaseous exchange which resulted in decrease of photosynthesis is associated with inhibition of several enzymes related to the Calvin cycle such as RuBisCo. In addition, salt stress decreases photosynthetic pigments such as chlorophyll and carotenoid which has important role in photosynthesis.
Sulfur (S) is one of six macronutrients needed for proper plant growth and development. In our previous work, we found that sulfur nutrition has significant role in ameliorating the damaged in photosynthetic organelles caused by Fe-deficiency in oilseed rape (Muneer et al., 2014). In addition, application of sulfur mitigated the adverse effects of heavy metals stress by enhancing plant growth, chlorophyll content and net photosynthetic rate. Despite extensive researches attempting to elucidate the interactions between external sulfur supplies and stress tolerance, to our knowledge, the responses of the photosynthetic mechanism to combined S deficiency and salt stress have not yet been fully investigated.
In this study, therefore, we hypothesized that S nutrition affects photosynthetic organs to salt stress, so that may involve in alleviating negative impact of salt stress in Kentucky bluegrass. To test this hypothesis, the responses of photosynthetic parameters, thylakoid protein complexes and ion uptake were compared for 21 days of four S and salt stress combined treatments; sulfur sufficient without salt stress (+S/non-salt, control), present of sulfur with salt stress (+S/salt), sulfur deprivation without salt stress (-S/non-salt) and sulfur deprivation and salt stress (-S/salt)
