RESPONSES TO WATER-STRESS OF APOPLASTIC WATER FRACTION AND BULK MODULUS OF ELASTICITY IN SUNFLOWER (HELIANTHUS-ANNUUS L) GENOTYPES OF CONTRASTING CAPACITY FOR OSMOTIC ADJUSTMENT
被引:29
作者:
CHIMENTI, CA
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机构:IFEVA, Facultad de Agronomía, Universidad de Buenos Aires, Buenos Aires, 1417
CHIMENTI, CA
HALL, AJ
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h-index: 0
机构:IFEVA, Facultad de Agronomía, Universidad de Buenos Aires, Buenos Aires, 1417
HALL, AJ
机构:
[1] IFEVA, Facultad de Agronomía, Universidad de Buenos Aires, Buenos Aires, 1417
APOPLASTIC WATER FRACTION;
BULK MODULUS OF ELASTICITY;
HELIANTHUS ANNUUS;
OSMOTIC ADJUSTMENT;
D O I:
10.1007/BF02185486
中图分类号:
S3 [农学(农艺学)];
学科分类号:
0901 ;
摘要:
The responses to water stress of the bulk modulus of elasticity (epsilon) and the apoplastic water fraction were examined using six sunflower cultivars of differing capacity for osmotic adjustment (OA). Water stress did not affect the partitioning of water between apoplastic (ca. 20%) and symplastic fractions in leaves which expanded during the exposure to stress in any genotype. Hence, no genotype-linked effects on either the buffering of cell water status during stress or on the estimates of bulk leaf osmotic potential could be expected. Genotypes differed in the degree of change in epsilon (estimated from pressure/volume [PN] curves) and OA (estimated using both In RWC/ In Psi o plots and PN curves) induced by exposure to stress. In three genotypes epsilon increased significantly (p = 0.05) as a consequence of stress, in another three change were small. OA was the only attribute of the three examined that could have contributed to turgor maintenance under stress. There was a strong negative association between leaf expansion and degree of OA across genotypes (r = -0.91) and a strong positive one between OA and E (r = 0.94). However all genotypes evidenced some degree of OA. These results are consistent with part of the genotype differences in OA being attributable to variations in leaf expansion during exposure to stress.