Physiological Responses to Mineral-Excessive Conditions: Mineral Uptake and Carbohydrate Partitioning in Tomato Plants

다국어 초록 (Multilingual Abstract)

The shortage or surplus of minerals directly affects overall physiological metabolism of plants; especially, it strongly influences carbohydrate metabolism as a primary response. We have studied mineral uptake, synthesis and partitioning of soluble carbohydrates, and the relationship between them in N, P or K-excessive tomato plants, and examined the interaction between soluble carbohydrates and mineral elements. Fourweeks-old tomato plants were grown in a hydroponic growth container adjusted with excessive N (20.0 mmol L<SUP>-1</SUP> Ca(NO₃)₂?4H₂O and 20.0 mmol L<SUP>-1 </SUP>KNO₃), P (2.0 mmol L-1 KH₂PO₄), and K (20.0 mmol L-1 KNO₃), respectively, for 30 days. Shoot growth rates were significantly influenced by excessive N or K, but not by excessive P. The concentrations of water soluble N (nitrate and ammonium), P and K were clearly different with each tissue of tomato plants as well as the mineral conditions. The NPK accumulation in all treatments was as follows; fully expanded leaves (48%) > stem (19%) = roots (16%) = petioles (15%) > emerging leaves (1). K-excessive condition extremely contributed to a remarkable increase in the ratio, which ranged from 2.79 to 10.34, and particularly potassium was dominantly accumulated in petioles, stem and roots. Fresh weight-based soluble sugar concentration was the greatest in NPK-sufficient condition (154.8 mg g<SUP>-1</SUP>) and followed by K-excessive (141.6), N-excessive (129.2) and P-excessive (127.7); whereas starch was the highest in K-excessive (167.0 mg g<SUP>-1</SUP>) and followed by P-excessive (146.1), NPK-sufficient (138.2) and N-excessive (109.7). Soluble sugar showed positive correlation with dry weight-based total N content (p<0.01) whereas was negatively correlated with soluble P (p<0.01) and dry weight-based total P (p<0.01). On the other hand, starch production was negatively influenced by total N (p<0.001), but, it showed positive relation with total K concentration (p<0.05). This study shows that uptake pattern of NPK and production and partitioning of soluble carbohydrate were substantially different from each mineral, and the relationship between water soluble- and dry weight-based-mineral was positive.

목차 (Table of Contents)

• Introduction
• Materials and Method
• Results and Discussion
• Conclusions
• References