Salicylic acid supplementation improves photosynthesis and growth in mustard through changes in proline accumulation and ethylene formation under drought stress

Abstract

Drought stress is becoming a major threat to plant productivity loss in agricultural system. The present study was carried out to evaluate the physiological and biochemical alterations induced by salicylic acid (SA) in mustard plant under moderate drought stress conditions. Therefore, a pot culture experiment was conducted to test whether SA application at concentration of 0.5 mM through foliar spray could protect the mustard (Brassica juncea L.) cultivar Pusa Jai Kisan subjected to drought stress on the basis of growth and photosynthesis. The treatments were as follows: (i) 100% FC + 0 mM SA, (ii) 50% FC + 0 mM SA, (iii) 100% FC + 0.5 mM SA and (iv) 50% FC + 0.5 mM SA. The control treatment received 100% field capacity (FC) irrigation, whereas moderate drought stress corresponded to 50% field capacity. Plants subjected to drought stress caused significant reduction in growth and photosynthetic parameters, activity of ribulose 1,5-bisphosphate carboxylase (Rubisco), nitrate reductase (NR), ATP-sulfurylase (ATPS) which accounted for decreased nitrogen (N) and sulfur (S) assimilation. Whereas, a pronounced increase was observed in proline metabolism. Exogenously applied 0.5 mM SA alleviated the stress by increasing the proline production through the increase in γ-glutamyl kinase (GK) and decrease in proline oxidase (PROX) activity. In addition SA application restricted the ethylene formation by inhibiting the 1-aminocyclopropane carboxylic acid synthase (ACS) activity more conspicuously under moderate drought stress than no stress. These findings reflect that SA application alleviates the drought-induced decrease in growth and photosynthesis through increased proline content. Higher proline content was a result of increased N and S assimilation and increased synthesis of proline synthesizing enzyme which lowers the oxidative stress in mustard.

Photosynthetic Activity of Superior Varieties and Local Cassava (Manihot esculenta Crantz) Indonesia

“…CO 2 in cassava varieties yangt Singgah low may result in a slow rate of photosynthesis, although only slightly faster than the local varieties Ketan. This was confirmed by Chavez et al (2003) and Nazar et al (2015), that the reduction in CO 2 concentration limits the diffusion process and affects photosynthesis. Differences in the rate of photosynthesis between varieties strengthen the research Mahon et al and Tan that the photosynthesis rate ranges from 15-45 mg CO 2 dn -2 hour -1…”

“…The process of photosynthesis resulted in CO 2 levels in the cell decreased. According to Chaves et al (2003) and Nazar et al (2015), that the decrease in stomatal CO 2 concentration in the diffusion limitation effect on photosynthesis. The reaction of photosynthesis requires CO 2 , so that the high CO 2 on plants and cassava enabling the rising rate of photosynthesis.…”

Influence of plant-growth-promoting bacteria on germination, growth and nutrients’ uptake ofOnobrychis sativaL. under drought stress

“…The most important problems of arid and semiarid rangelands are drought and water shortage that affect the growth and development of plants (Zandi Esfahan & Azarnivand 2012). Drought stress is one of the main environmental factors limiting plant growth; the most common cause of that is increase in temperature and reduction in available water to plants (Nazar et al 2015). Water shortage as a factor limiting in the germination stage inhibits growth and establishment of the plant and reduces the crop production (Yan 2015).…”

Mycorrhizal Inoculation Modulates Root Morphology and Root Phytohormone Responses in Trifoliate Orange under Drought Stress

“…Soil drought stress (DS) is one of the important abiotic stresses, strongly limiting crop growth and yield (Nazar et al, 2015). Roots are directly in touch with soil moisture changes, and thus, the damage of plant to drought is firstly in roots.…”