ABSTRACT.
Foliar application of 5-Aminolevulinic acid alleviated high temperature and drought stresses on wheat plants at seedling stage

Mohamed Suliman Eltyeb Suliman1, 2, Safiya Babiker Mustafa Elradi1, 2, Nimir Eltyb Ahmed Nimir1, 2, Guisheng Zhou1, 3*, Guanglong Zhu1, 3, Muhi Eldeen Hussien Ibrahim1, 4, and Adam Yousif Adam Ali1, 5
 
Wheat (Triticum aestivum L.) seedling establishment is very sensitive to temperature and drought stresses. The present study was conducted to investigate the effects of foliar exogenous 5-aminolevulinic acid (5-ALA) application on wheatseedling under different temperature (25, 30, and 35 ºC) and water regimes (normal and 65% watering). Five different levels of 5-ALA (0, 25, 50, 100 and 150 mg L-1) were applied as foliar application. Leaf area, stem diameter, shoot androot lengths, fresh and dry weights of shoot and root, and physiological parameters were measured. Drought stress (W2) decreased leaf area by 14.9% compared with normal watering (W1). High temperature (35 ºC) increased malondialdehyde (MDA) content by 72.1% compared with control (25 ºC). 35 ºC with W2 reduced root and shoot dry weights by 71.8% and 51.9% relative to 25 ºC and W1. At 35 ºC, 25 mg L-15-ALA increased root length by 17.1% and 3.4% at W1 and W2, respectively. 150 mg L-1 5-ALA increased root fresh weight by101.0% compared with 0 mg L-1 5-ALA at W1 and 35 ºC. The highest protein content (8.35 mg g-1 FW) was achieved at the interaction between W2, 35 ºC and 50 mg L-1 5-ALA.At W2 and 35 ºC, 150 mg L-1 5-ALA increased proline content by 66.5% relative to 0 mg L-1. The results of the presentstudy suggest that foliar application of 5-ALA could be useful to alleviate the temperature and/or drought stresses of wheat seedling.
Keywords: 5-Aminolevulinic acid, crop establishment, high temperature, Triticum aestivum, water regime.
1Yangzhou University, Joint International Research Laboratory of Agriculture and Agri-Product Safety of the Ministry of Education of China, Yangzhou 225009, China.
2University of Khartoum, Faculty of Agriculture, 11115 Khartoum, Sudan.
3Yangzhou University, Jiangsu Co-Innovation Center for Modern Production Technology of Grain Crops, Yangzhou 225009, China.
*Corresponding author (gszhou@yzu.edu.cn).
4Sudan University of Science and Technology, Department of Agronomy, College of Agricultural Studies, Khartoum 13311, Sudan.
5University of Al Qadarif, Department of Agronomy, College of Agricultural and Environment Science, Al Qadarif 32214, Sudan.