תפריט נגישות
ניגודיות עדינהניגודיות גבוהה
מונוכרום
הדגשת קישורים
חסימת אנימציה
פונט קריא
סגור
איפוס הגדרות נגישות
להורדת מודול נגישות חינם תפריט נגישותניגודיות עדינהניגודיות גבוההמונוכרוםהדגשת קישוריםחסימת אנימציהפונט קריאסגוראיפוס הגדרות נגישותלהורדת מודול נגישות חינםSweet basil (Ocimum basilicum L.) is a plant of tropical origin which is susceptible to chilling. The objective of the present work was to reveal the relationship between membrane lipid composition and chilling sensitivity of basil leaves. For this purpose, a comparative study was performed with 2 basil cultivars (cv. 79 and cv. 10), which vary in their susceptibility to chilling, analyzing differences in their critical temperatures for appearance of visual chilling injury (CI) symptoms, their phase transition temperatures and their fatty acid (FA) composition of their disaturated membrane phosphatidylglycerol (PG) and phosphatidylcholine (PC). The phase transition temperatures were derived from Arrhenius plots of the respiration rates. The composition of FA in the polar lipids were analyzed by gas-liquid chromatography. Results show that the phase transition temperature of the sensitive cultivar (cv. 79) increased from 12.5 to 17° C during 1–6 days of incubation, whereas that of the less sensitive cultivar (cv. 10) — was much lower and remained between 3–5°C throughout storage. These variations in the transition temperatures of the two cultivars may presumably result from the differences in the FA composition of their disaturated membrane PG and PC. Thus, leaves of the chilling-sensitive cultivar (cv. 79) showed a reduction and an increase in the composition of 18:1 and 16:0 FA, respectively, of PG and PC, as compared with leaves of the less susceptible cultivar (cv 10). The results suggest that these two PG and PC FA, present in the chloroplast membranes of basil leaves, are closely associated with the chilling sensitivity of the two tested basil cultivars. These findings further confirm that the chilling sensitivity of higher plants is affected by the content of saturated PG and PC fatty acids.
Sweet basil (Ocimum basilicum L.) is a plant of tropical origin which is susceptible to chilling. The objective of the present work was to reveal the relationship between membrane lipid composition and chilling sensitivity of basil leaves. For this purpose, a comparative study was performed with 2 basil cultivars (cv. 79 and cv. 10), which vary in their susceptibility to chilling, analyzing differences in their critical temperatures for appearance of visual chilling injury (CI) symptoms, their phase transition temperatures and their fatty acid (FA) composition of their disaturated membrane phosphatidylglycerol (PG) and phosphatidylcholine (PC). The phase transition temperatures were derived from Arrhenius plots of the respiration rates. The composition of FA in the polar lipids were analyzed by gas-liquid chromatography. Results show that the phase transition temperature of the sensitive cultivar (cv. 79) increased from 12.5 to 17° C during 1–6 days of incubation, whereas that of the less sensitive cultivar (cv. 10) — was much lower and remained between 3–5°C throughout storage. These variations in the transition temperatures of the two cultivars may presumably result from the differences in the FA composition of their disaturated membrane PG and PC. Thus, leaves of the chilling-sensitive cultivar (cv. 79) showed a reduction and an increase in the composition of 18:1 and 16:0 FA, respectively, of PG and PC, as compared with leaves of the less susceptible cultivar (cv 10). The results suggest that these two PG and PC FA, present in the chloroplast membranes of basil leaves, are closely associated with the chilling sensitivity of the two tested basil cultivars. These findings further confirm that the chilling sensitivity of higher plants is affected by the content of saturated PG and PC fatty acids.
