Abstract
Quercus fabri Hance, Quercus serrata Thunb, Quercus acutissima Carruth, and Quercus variabilis BL are four Chinese oak species commonly used for forestation. To ensure the survival of seedlings, we first need to understand the differences in drought resistance of the four oak species at the seedling stage, and comprehensively evaluate their drought resistance capabilities. The four oak seedlings were divided into drought-rewatering treatment group and well watered samples (control group). For the seedlings of the drought-rewatering treatment group, drought stress lasting 31 days was used, and then re-watering for 5 days. The water parameters, osmotic solutes content, antioxidant enzyme activity and photosynthesis parameters of the seedlings in the two groups were measured every 5 days. Compared with the control group, the relative water content, water potential, net photosynthetic rate, transpiration rate, and stomatal conductance levels of the four oaks all showed a downward trend under continuous drought stress, and showed an upward trend after rehydration. The soluble protein, soluble sugar, proline, peroxidase, superoxide dismutase and catalase content of the four oaks increased first and then decreased under drought stress, and then increased after rehydration. The content of glycine betaine and malondialdehyde continued to increase, and gradually decreased after rehydration. The weight of each index was calculated by principal component analysis, and then the comprehensive evaluation of each index was carried out through the membership function method. The drought resistance levels of the four oak species were as follows: Q. serrata > Q. fabri > Q. variabilis > Q. acutissima.
Highlights
With rising global temperatures and frequent extreme phenomena, 64% of the world’s land is already under drought stress, which has seriously affected the normal growth and development of many plants and crops [1]
Under continuous drought stress, the relative water content and water potential of the four oak species decreased to different degrees, which content and water potential of the four oak species decreased to different degrees, which indicated that the four oak species could absorb more water by reducing Water potential (Ψw) to resist indicated that the four oak species could absorb more water by reducing Ψw to resist drought stress
When drought stress reached the limit of plant self-regulation, we found that the levels of Pro and Soluble protein (SP) of the four oak species began to decline at day 26
Summary
With rising global temperatures and frequent extreme phenomena, 64% of the world’s land is already under drought stress, which has seriously affected the normal growth and development of many plants and crops [1]. Even southern regions with abundant rainfall are often affected by seasonal drought, which is a major factor that limits the normal growth and development of plants [3]. When plants are under drought stress, the plant water balance is severely affected, and normal physiological processes are compromised [4]. Plants close their stomata to reduce water loss, which can limit the supply of CO2 and lead to reduced photosynthesis Reactive oxygen species (ROS) metabolism is the primary response of plants to stress [6]. Drought stress can lead to the disorder of production and elimination of ROS in plants, and excessive accumulation of ROS causes oxidative stress [7]. To protect themselves from oxidative stress, plants produce antioxidant enzymes and nonenzymatic substances that scavenge ROS [8]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
