Effects of Drought Stress Induced by Hypertonic Polyethylene Glycol (PEG-6000) on Passiflora edulis Sims Physiological Properties

Abstract

Passion fruit is known to be sensitive to drought, and in order to study the physiological and biochemical changes that occur in passion fruit seedlings under drought stress, a hypertonic polyethylene glycol (PEG) solution (5%, 10%, 15%, and 20%) was used to simulate drought stress in passion fruit seedlings. We explored the physiological changes in passion fruit seedlings under drought stress induced by PEG to elucidate their response to drought stress and provide a theoretical basis for drought-resistant cultivation of passion fruit seedlings. The results show that drought stress induced by PEG had a significant effect on the growth and physiological indices of passion fruit. Drought stress significantly decreased fresh weight, chlorophyll content, and root vitality. Conversely, the contents of soluble protein (SP), proline (Pro), and malondialdehyde (MDA) increased gradually with the increasing PEG concentration and prolonged stress duration. After nine days, the SP, Pro and MDA contents were higher in passion fruit leaves and roots under 20% PEG treatments compared with the control. Additionally, with the increase in drought time, the activities of antioxidant enzymes such as peroxidase (POD), superoxide dismutase (SOD) and catalase (CAT) showed an increasing trend and then a decreasing trend, and they reached the highest value at the sixth day of drought stress. After rehydration, SP, Pro and MDA contents in the leaves and roots of passion fruit seedlings was reduced. Among all the stress treatments, 20% PEG had the most significant effect on passion fruit seedlings. Therefore, our study demonstrated sensitive concentrations of PEG to simulate drought stress on passion fruit and revealed the physiological adaptability of passion fruit to drought stress.

Seed Characteristics of Passion Fruit (Passiflora edulis f. flavicarpa) Rootstocks with Different Genotypes and Responses of Their Seedlings to Drought Stress

“…As previously reported, exceeding the total oxidation potential of cells will induce oxidative stress, affecting plant growth (Qi et al, 2023) synthesis after drought stress. It should also be noted that H 2 O 2 in leaves can be accurately regulated through the complex regulation of CAT mRNA (Luna et al, 2004) and that H 2 O 2 can reduce the activity of POD, resulting in the accumulation of more H 2 O 2 in plants (Song et al, 2016).…”

Effects of Progressive Drought Stress on the Growth, Ornamental Values, and Physiological Properties of Begonia semperflorens

“…Under drought stress, osmotic adjustment substances will accumulate to maintain the cell osmotic pressure of plants and to ensure the orderly conduct of a series of physiological and biochemical reactions in plant cells [32,33]. Osmotic adjustment substances protect macromolecular substances.…”

Water-Retaining Polymer and Planting Pit Size on Chlorophyll Index, Gas Exchange and Yield of Sour Passion Fruit with Deficit Irrigation

“…The limitation of water availability in sour passion fruit can cause oxidative stress [ 7 ], negatively affecting several physiological processes, such as a reduction in chlorophyll levels [ 4 ], gas exchange [ 5 ], assimilation of carbon dioxide [ 8 , 9 ], and in fruit yield [ 4 , 10 ]. In this regard, the use of irrigation associated with techniques that allow for greater storage and retention of water in the soil close to the absorbent roots can increase irrigation efficiency with reflections on greater water availability to the plant.…”