Abstract: In order to clarify whether existed autophagy phenomenon in sugar beet under salt stress and its relationship with plant salt-resistant physiological characteristics, the self-phage occurrence, reactive oxygen species content, osmosis regulating substance content and their relationship under different salt gradients were studied with salt-resistant sugar beet variety LS2004 and salt-sensitive sugar beet variety KWS7125 as experimental materials. The results showed that salt stress could induce autophagy in sugar beet seedlings. Autophagy was involved in the defense process of sugar beet seedlings against salt stress. The specific manifestation was that autophagy increased with the increase of salt concentration. Under the salt stress condition of 300 mmol/L, LS2004 had the strongest autophagy and the largest number of autophagosomes, which was 1.22 times that of KWS7125. The hydrogen peroxide content of KWS7125 and LS2004 reached the peak under the treatment of 200 mmol/L, which were increased by 40.06% and 41.54% respectively compared with that of the control. Under each treatment, the superoxide anion content and relative electrical conductivity of KWS7125 were higher than those of LS2004. The soluble protein content, proline content and total soluble sugar content of LS2004 firstly increased and then decreased with the increase of salt concentration, but there were differences in change rules with KWS7125. In summary, autophagy existed in sugar beet seedlings under salt stress, and the comprehensive effect of autophagy, alleviating oxidative damage, and osmotic adjustment substance content could be used by sugar beet seedlings to improve the salt tolerance of sugar beet.

Key words: Sugar beet, Salt tolerance, Autophagy, Active oxygen, Physiological characteristics

CLC Number: 

• S566.3