Effects of Different Concentrations of Exogenous Trehalose on Freezing Resistance of Sugar Beet Seedlings
In order to clarify the regulatory effect of trehalose on the freezing resistance of sugar beet seedlings,the sugar beet variety'KWS1197'was used as the experimental material,and different concentrations of treha-lose(0,5,10,15,20 and 25mmol/L)were sprayed on the leaves under freezing stress by means of indoor soil culture.After 5h of treatment at-3℃,the seedlings were treated with trehalose.The changes of freezing death rate,dry and fresh weight,photosynthetic pigment content,relative electrical conductivity,malondialdehyde content,antioxidant enzyme activity and osmotic regulation substance content of beet seedlings were analyzed.The results showed that freezing stress significantly affected above-ground dry and fresh weight,osmotic regula-tory substances,antioxidant enzyme activity,seedling mortality,relative electrical conductivity(REC)and ma-londialdehyde(MDA)content of sugar beet seedlings.Under freezing stress,trehalose spraying with appropriate concentration can effectively alleviate the oxidative damage of freezing on beet seedlings,and there is a certain concentration effect.Compared with spraying distilled water underfreezingstress,trehalose concentration of 15mmol/L has the best freezing resistance effect.The freezing death rate,relative conductivity and malondialde-hyde content of sugar beet seedlings were significantly decreased by 58.50%,24.21%and 33.65%,respec-tively.Shoot dry and fresh weight,total chlorophyll content,peroxidase(POD)activity,superoxide dismutase(SOD)activity,soluble sugar content and proline content were significantly increased by 43.75%,63.90%,168.60%,177.77%,11.61%and 128.20%,respectively.Trehalose spraying on the leaves can effectively al-leviate the oxidative damage of beet seedlings under freezing stress and improve the freezing resistance of beet seedlings,among which 15mmol/L trehalose treatment has the best effect.
国家科技期刊平台
NSTL
万方数据
