Changes in nitrogen metabolism and antioxidant enzyme activities of maize tassel in black soils region of northeast China.

Hongwen Xu,Yan Lu,Fengbin Song,Zhiming Xie

doi:10.3389/fpls.2014.00515

Abstract

Two varieties of maize (Zea mays L.) grown in fields in black soils of northeast China were tested to study the dynamic changes of nitrogen metabolism and antioxidant enzyme activity in tassels of maize. Results showed that antioxidant enzyme activity in tassels of maize increased first and then decreased with the growing of maize, and reached peak value at shedding period. Pattern of proline was consistent with antioxidant enzyme activity, showing that osmotic adjustment could protect many enzymes, which are important for cell metabolism. Continuous reduction of soluble protein content along with the growing of maize was observed in the study, which indicated that quantitative material and energy were provided for pollen formation. Besides, another major cause was that a large proportion of nitrogen was used for the composition of structural protein. Nitrate nitrogen concentrations of tassels were more variable than ammonium nitrogen, which showed that nitrate nitrogen was the favored nitrogen source for maize.

Highlights

Maize (Zea mays L.) pollination is one of the most important and complicated phases of crop development, pollination in maize occurs only if pollen shed by the tassel is captured by the stigmas on the ear (Kaleita et al, 2006)
Further study is needed on the role of nitrogen metabolism in agricultural research, because it involves in pollen grain formation and quality improvement
SOLUBLE PROTEIN AND PROLINE CONTENT Soluble protein and proline content were analyzed from tasseling to maturing period (Figure 1)

Summary

Introduction

Maize (Zea mays L.) pollination is one of the most important and complicated phases of crop development, pollination in maize occurs only if pollen shed by the tassel is captured by the stigmas (silks) on the ear (Kaleita et al, 2006). Nitrogen is referred to be the most important mineral nutrient, whose availability is most likely to limit plant growth. Among these important plant nutrients, nitrogen is known as an important element to synthesize the essential cellular components for the processes of pollination and fertilization. As the major nitrogenous compounds in plants, amino acids play key roles in supplying substrates for different kinds of cellular metabolism, such as energy generation and cell wall synthesis, which are imperative to the growth and developmental processes of plants (Azevedo et al, 2006; Ferreira et al, 2006). Nitrate and ammonium nitrogen as principal nitrogen sources play essential roles in various physiological and metabolic functions in plants. Nitrate can be absorbed by plant roots and be converted to ammonium by the sequential reductive action of the enzymes (Yang et al, 2013)

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