Nandula V K, Foster J G, Foy C L
Department of Plant Pathology, Physiology and Weed Science, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061-0331, USA.
J Agric Food Chem. 2000 Sep;48(9):3930-4. doi: 10.1021/jf991145w.
The relationship between the organic nitrogen status of Egyptian broomrape and one of its hosts, carrot, was studied by comparing amino acid profiles of leaf and root tissues of nonparasitized and broomrape-parasitized carrot plants and by analyzing amino acid profiles of broomrape at different growth stages. Total N concentrations, expressed as a percentage of the dry weight of the tissues, were similar in leaves of nonparasitized and parasitized carrot plants but were lower in parasitized roots than in nonparasitized roots. In both dry and germinated broomrape seeds, N concentrations were lower than or similar to those in broomrape tubercles, shoots, or callus. Individual amino acid concentrations in hydrolysates of leaves of parasitized carrot plants tended to be similar to or greater than those in hydrolysates of nonparasitized carrot plants. Roots of parasitized plants tended to have similar or lower amino acid concentrations than roots of nonparasitized plants. Dry and germinated broomrape seeds had similar amino acid profiles, but individual amino acid concentrations were lower than in the other broomrape tissues examined. The broomrape shoot tended to have lower amino acid concentrations than the tubercle and callus. Free amino acid profiles of leaves and roots of parasitized plants paralleled those of nonparasitized plants, respectively. Individual free amino acids tended to occur at similar or lower levels in dry and germinated broomrape seeds than in the tubercle, shoot, or callus. Free amino acid composition of the broomrape tubercle was similar to that of the parasitized root. Arginine and alanine concentrations in broomrape callus were dramatically higher than those of other amino acids in this or other tissues investigated. These results indicate that changes in the composition of both free and bound amino acids in carrot are associated with broomrape parasitism.
通过比较未被寄生和被列当属植物寄生的胡萝卜植株叶片和根系组织的氨基酸谱，并分析不同生长阶段列当属植物的氨基酸谱，研究了埃及列当属植物的有机氮状况与其寄主之一胡萝卜之间的关系。以组织干重百分比表示的总氮浓度，在未被寄生和被寄生的胡萝卜植株叶片中相似，但在被寄生的根系中低于未被寄生的根系。在干列当属种子和发芽的列当属种子中，氮浓度低于或类似于列当属瘤、地上部分或愈伤组织中的氮浓度。被寄生的胡萝卜植株叶片水解产物中的个别氨基酸浓度往往与未被寄生的胡萝卜植株水解产物中的相似或更高。被寄生植株的根系氨基酸浓度往往与未被寄生植株的根系相似或更低。干列当属种子和发芽的列当属种子具有相似的氨基酸谱，但个别氨基酸浓度低于所检测的其他列当属组织。列当属地上部分的氨基酸浓度往往低于瘤和愈伤组织。被寄生植株叶片和根系的游离氨基酸谱分别与未被寄生植株的相似。干列当属种子和发芽的列当属种子中的个别游离氨基酸含量往往低于瘤、地上部分或愈伤组织。列当属瘤的游离氨基酸组成与被寄生根系的相似。列当属愈伤组织中的精氨酸和丙氨酸浓度显著高于该组织或其他所研究组织中的其他氨基酸浓度。这些结果表明，胡萝卜中游离和结合氨基酸组成的变化与列当属植物寄生有关。
