Carbon and nitrogen partitioning of transgenic rice T2A-1 (Cry2A*) with different nitrogen treatments

Lin Ling,Kangxu Wang,Cougui Cao,Mingli Cai,Yang Jiang,Xuexue Li

doi:10.1038/s41598-019-41267-1

Abstract

Nitrogen (N) and carbon(C) metabolisms in plants were investigated to assess different responses of Bt and non-Bt rice to different N treatments. T2A-1 (Bt rice variety) inserted with Cry2A* protein to resist Lepidoptera and its parental line MH63 was adopted in this study. The total N accumulation presented no statistical difference. But nitrogen contents in different parts of rice plant were significantly different between the two lines, especially on leaf and spike part. This study revealed that the nitrogen in leaf of T2A-1 was far more than that of MH63; however, the nitrogen in spike of T2A-1 was less than that of MH63. In addition, MH63 assimilated more carbon than T2A-1. However, the distribution proportion of carbon in leaf, stem and spike of T2A-1 and MH63 were both 1:1:1. What’s more, our study of the difference in metabolism pathway based on proteomics analysis provided more insights on the responses of two lines of Bt and non-Bt rice to different N treatments. And amino acid metabolism, energy metabolism, and carbohydrate metabolism presented significant difference between two lines. In addition, the number of differentially expressed proteins with N deficiency treatment was almost twice as many as that with normal N treatment. It could be inferred that the insertion of Cry2A* in T2A-1 may bring about effects on carbon and nitrogen allocation and related metabolisms, especially under N deficiency environment.

Highlights

Nitrogen (N) and carbon(C) metabolisms in plants were investigated to assess different responses of Bt and non-Bt rice to different N treatments
It could be inferred that the insertion of Cry2A* in T2A-1 may bring about effects on carbon and nitrogen allocation and related metabolisms, especially under N deficiency environment
Significant differences in dry matter of each part including stem, leaf and spike were observed between plants of MH63 and T2A-1(Table 1) under different nitrogen treatments

Summary

Introduction

Nitrogen (N) and carbon(C) metabolisms in plants were investigated to assess different responses of Bt and non-Bt rice to different N treatments. Several previous studies demonstrated the differences in the agronomy traits and physiological metabolism in some rice lines inserted by exogenous insect-resistant genes[13,14,15,16,17,18,19] These differences included reduced plant heights and root lengths[14], fewer grains per panicle[17], decreased setting rates[5,14,17,18,20], and so on, which in turn led to reductions in grain yield. This study was aimed to (1) explore the distribution and allocation of C and N in transgenic Cry2A* rice (T2A-1) and its conventional (non-transgenic) parent line MH63, a widely used indica cytoplasm male sterile (CMS) restorer rice line in Asia[5]; (2) attempt to discover the differences of proteins expression related to C and N metabolism under different N treatments combining physiological indicators of C and N metabolism with proteomics analysis

Objectives

Methods

Results

Conclusion