Molecular Basis of Freezing Injury and Tolerance

Effect of low temperature on flavonoids, oxygen radical absorbance capacity values and major components of winter sweet spinach (Spinacia oleracea L.)

“…SPAD values on the same harvest days increased in the order Asagiri > Mahoroba > Wakakusa in both WST and control cultivation. Although low temperature markedly decreases CO 2 assimilation in plants, 20 the total sugar concentrations in all varieties of winter sweet spinach markedly increased as follows (Table 3) were identical in all varieties, only the sucrose concentration was increased markedly by the treatment, whereas the glucose and fructose concentrations showed modest increases. Therefore, sucrose is a major sugar component in winter sweet spinach.…”

“…Although low temperature markedly decreases CO 2 assimilation in plants, the total sugar concentrations in all varieties of winter sweet spinach markedly increased as follows (Table ): by 4.3‐fold in Asagiri, 4.8‐fold in Mahoroba and 4.6‐fold in Wakakusa after 25 days of WST (26 December) compared with those before WST (1 December), reaching 9.4‐fold in Asagiri, 7.3‐fold in Mahoroba and 6.8‐fold in Wakakusa after 40 days of WST (10 January). These concentrations (ranging from 53.8 to 54.8 g kg −1 FW) were significantly higher than the concentrations under the cultivation without WST (25.8–35.7 g kg −1 FW).…”

Sulphate induced accumulation of glutathione and frost‐tolerance of spinach leaf tissue

“…Sulfhydryl groups have been suggested ,as a factor in freezing tolerance of plants (Levitt et al 1961, Schtnuetz et al 1961. Levitt (1972) proposed that freezing injury was caused by confortnational changes of protein due to oxidation of protein sulfhydrj'l groups by freeze-dehydration. In frosf-toleranf tissue infertnolecular SS bonding would be prevented.…”