EFFECT OF NUTRITIONAL STRESS ON PLANT COMPOSITION: II. CHANGES IN SUGAR AND AMIDE NITROGEN CONTENT OF NORMAL AND SULFUR-DEFICIENT ALFALFA DURING GROWTH

• Published in: Plant and soil 1961-04, Vol.14 (2), p.176-186
• Main Authors: RENDIG, V. V., McCOMB, E. A.
• Format: Article
• Language: English
• Subjects: Alfalfa; Amides; Chemical composition; Leaves; Nitrogen; Paper chromatography; Plants; Sugars; Sulfates; Sulfur
• ISSN: 0032-079X; 1573-5036
• DOI: 10.1007/BF01394566

Nutritional stress imposed on the alfalfa plant by an inadequate supply of sulfur altered the course of changes in composition which normally accompany its ontogenetic development. Of the constituents examined the greatest alteration occurred in the "amide" nitrogen (asparagine) fraction. During the course of development of plants well supplied with sulfur the level of this nitrogen fraction decreased but in the sulfur-deficient plant it increased. Among the sugars the effect of greatest magnitude appeared to be the almost complete absence of glucose in the stems of young plants not receiving adequate sulfur. Subsequent tests have revealed that the divergence is even more dramatic if only the upper stems are used for this comparison since the reducing sugars normally are most abundant in this part of the plant. The relationship of sulfur deficiency to the occurrence of sucrose and fructose appeared to be less intimate. The presence of these sugars in sulfur-deficient plants was always indicated but at subnormal levels. Throughout the course of ontogenetic development the fluctuations in sucrose and fructose followed a pattern similar to that shown in the sulfur-adequate plants.