Effects of nitrogen and phosphorus on the microstructure and ultrastructure of tomato leaves (Solanum lycopersicum)

ABSTRACT

This study aims to evaluate the effects of nitrogen (N) and phosphorus (P) on tomato leaves at the microscale in order to propose new methods to detect N and P conditions of plants. N and P solutions composed of three N levels (N0.25, 1.75; N1, 7; and N1.5, 10.5 mmol L⁻¹) and three P levels (P0.25, 0.17; P1, 0.67; and P1.5, 1.01 mmol L⁻¹) with ten replications. Results showed a significant decrease in the leaf thickness among plants treated with N0.25, N1.5N and P0.25, whereas showed an increase among plants treated with P1.5 (p < 0.05). Stomatal density was reduced in P0.25- and N0.25-treated plants, whereas increased in N1.5- and P1.5-treated plants (p < 0.05). Moreover, N0.25-treated plants showed reduced trichome density, whereas N1.5-treated plants exhibited the highestamount of trichome density (p < 0.05). The densest veins occurred in the leaves of P1.5P-treated plants, then density reduced in plants with N1.5, N1P1, N0.25, P0.25 treatments, in a decreasing order (p < 0.05).

KEYWORDS:

• microstructure
• ultrastructure
• leaf
• tomato
• phosphorus
• nitrogen

Acknowledgments

The authors acknowledge the assistance of their technical staff.

Funding

This work was supported by the National Natural Science Foundation of China (Grant Nos. 2014BAD08B03, 31401286, 61233006, 31201659, 51475216, and 31471413), the China Post-doctoral Science Foundation (Grant No. 2014M561593), the JiangSu Post-doctoral Science Foundation (Grant No. 1401066B) and the Scientific Research Foundation of Jiangsu University (Grant No. 14JDG068).