Comparative analysis of combined phosphorus and drought stress-responses in two winter wheat

Phosphorus stress and drought stress are common abiotic stresses. In this study, two winter wheat “Xindong20” and “Xindong23” were solution cultured and then treated with drought stress under conventional phosphorus level (CP: 1.0 mmol/L) and low phosphorus level (LP: 0.05 mmol /L), respectively. The results showed that with the increase of drought stress, the LP application was more conducive to the growth of root tips, length, forks, surfarea and root vitality of wheat. Under the LP treatment, the total phosphorus content of root at rewatered 3d was increased by 94.2% in Xindong20 wheat and decreased by 48.9% in Xindong23 wheat, compared with their respective samples at drought 0d. The LP treatment increased the percentage content of K and decreased the P and Ca percentage content. However, under CP treatment, the percentage content of Zn after rewatered 3 days were increased, compared with drought 7d. Based on the GeneChip analysis of root samples from drought 7d, the microarray results showed that 4577 and 202 differentially expressed genes were detected from Xindong20 and Xindong23, respectively. Among them, 89.9% of differentially expressed genes were involved in organelles and vesicles in Xindong20, and 69.8% were involved in genes encoding root anatomical structure, respiratory chain, electron transport chain, ion transport and enzyme activity in Xindong23. Therefore, the supply of low phosphorus has more effects on the drought tolerance of wheat, and the wheat with different drought tolerance has different regulatory genes. The higher drought-tolerant wheat has more genes up-regulation in response to drought stress.