Exogenous Application of Nitric Oxide Mitigates Water Stress and Reduces Natural Viral Disease Incidence of Tomato Plants Subjected to Deficit Irrigation
Amr Elkelish,
Mohamed F. M. Ibrahim,
Hatem Ashour,
Ahmed Bondok,
Soumya Mukherjee,
Tariq Aftab,
Mohamed Hikal,
Ahmed Abou El-Yazied,
Ehab Azab,
Adil A. Gobouri,
Mohamed Moustafa-Farag,
Amr A. Metwally,
Hany G. Abd El-Gawad
Affiliations
Amr Elkelish
Botany Department, Faculty of Science, Suez Canal University Ismailia, Ismailia 41522, Egypt
Mohamed F. M. Ibrahim
Department of Agricultural Botany, Faculty of Agriculture, Ain Shams University, Cairo 11566, Egypt
Hatem Ashour
Department of Agricultural Botany, Faculty of Agriculture, Ain Shams University, Cairo 11566, Egypt
Ahmed Bondok
Department of Plant Pathology, Faculty of Agriculture, Ain Shams University, Cairo 11566, Egypt
Soumya Mukherjee
Department of Botany, Jangipur College, University of Kalyani, Kalyani 742213, India
Tariq Aftab
Department of Botany, Aligarh Muslim University, Aligarh 202002, India
Mohamed Hikal
Department of Biochemistry, Faculty of Agriculture, Ain Shams University, Cairo 11566, Egypt
Ahmed Abou El-Yazied
Department of Horticulture, Faculty of Agriculture, Ain Shams University, Cairo 11566, Egypt
Ehab Azab
Department of Biotechnology, College of Science, Taif University, P.O. Box 11099, Taif 21944, Saudi Arabia
Adil A. Gobouri
Department of Chemistry, College of Science, Taif University, P.O. Box 11099, Taif 21944, Saudi Arabia
Mohamed Moustafa-Farag
Horticulture Research Institute, Agriculture Research Center, 9 Gmaa St, Giza 12619, Egypt
Amr A. Metwally
Department of Horticulture, Faculty of Agriculture, Ain Shams University, Cairo 11566, Egypt
Hany G. Abd El-Gawad
Department of Horticulture, Faculty of Agriculture, Ain Shams University, Cairo 11566, Egypt
The present work reveals the beneficial role of sodium nitroprusside (SNP; NO donor concentration: 50 and 100 µM) in mitigation of water stress accompanied by a reduction in viral disease incidence in tomato plants subjected to deficit irrigation. The plants were grown under two irrigation regimes: well-watered (WW; irrigated after the depletion of 55–60% of available soil water) and water deficit (WD; irrigated after the depletion of 85–90% of available soil water) in two seasons of 2018 and 2019. The results indicated that under water stress conditions, plant growth, chlorophyll, relative water content (RWC), and fruit yield were decreased. Conversely, water stress significantly increased the MDA, proline, soluble sugars, and antioxidant enzymes’ activities. Moreover, it was obvious a negligible increase in the fruit content from NO2 and NO3. Water-deficit stress, however, had a positive impact on reducing the percentage of viral disease (TMV and TYLCV) incidence on tomato plants. Similarly, SNP application in the form of foliar spray significantly reduced the disease incidence, the severity, and the relative concentrations of TMV and TYLCV in tomato plants raised under both WW and WD conditions. The treatment of SNP at 100 µM achieved better results and could be recommended to induce tomato plant tolerance to water stress. Thus, the present work highlights the role of NO (SNP) in the alleviation of water stress in tomato plants and subsequent reduction in viral disease incidence during deficit irrigation.
