Phosphorus and naphthalene acetic acid increased the seed yield by regulating carbon and nitrogen assimilation of flax

Yaping Xie; Huirong Duan; Limin Wang; Jianping Zhang; Kongjun Dong; Xingrong Wang; Yanjun Zhang; Yangchen Zhou; Wenjuan Li; Yanni Qi; Wei Zhao; Zhao Dang; Xingzhen Wang; Wen Li; Lirong Zhao

doi:10.3389/fpls.2023.1228755

Phosphorus and naphthalene acetic acid increased the seed yield by regulating carbon and nitrogen assimilation of flax

Front Plant Sci. 2023 Aug 30:14:1228755. doi: 10.3389/fpls.2023.1228755. eCollection 2023.

Authors

Yaping Xie^{1

2}, Huirong Duan³, Limin Wang¹, Jianping Zhang¹, Kongjun Dong¹, Xingrong Wang¹, Yanjun Zhang¹, Yangchen Zhou², Wenjuan Li¹, Yanni Qi¹, Wei Zhao¹, Zhao Dang¹, Xingzhen Wang¹, Wen Li¹, Lirong Zhao¹

Affiliations

¹ Crop Research Institute, Gansu Academy of Agricultural Sciences, Lanzhou, China.
² College of Agronomy, Gansu Agricultural University, Lanzhou, China.
³ Lanzhou Institute of Husbandry and Pharmaceutical Science, Chinese Academy of Agricultural Sciences, Lanzhou, China.

Abstract

To evaluate the impact of phosphorus (P) combined with exogenous NAA on flax yield, enhance flax P utilization efficiency and productivity, minimize resource inputs and mitigate negative environmental and human effects. Therefore, it is crucial to comprehend the physiological and biochemical responses of flax to P and naphthylacetic acid (NAA) in order to guide future agronomic management strategies for increasing seed yield. A randomized complete block design trial was conducted under semi-arid conditions in Northwest China, using a factorial split-plot to investigate the effects of three P (0, 67.5, and 135.0 kg P₂O₅ ha^-1) and three exogenous spray NAA levels (0, 20, and 40 mg NAA L^-1) on sucrose phosphate synthase (SPS) and diphosphoribulose carboxylase (Rubisco) activities as well as nitrogen (N) and P accumulation and translocation in flax. Results indicated that the SPS and Rubisco activities, N and P accumulation at flowering and maturity along with assimilation and translocation post-flowering, fruiting branches per plant, tillers per plant, capsules per plant, and seed yield were 95, 105, 14, 27, 55, 15, 13, 110, 103, 82, 16, 61, 8, and 13% greater in the P treatments compared to those in the zero P treatment, respectively. Moreover, those characteristics were observed to be greater with exogenous spray NAA treatments compared to that no spray NAA treatment. Additionally, the maximum SPS and Rubisco activities, N and P accumulation, assimilation post-flowering and translocation, capsules per plant, and seed yield were achieved with the application of 67.5 kg P₂O₅ ha^-1 with 20 mg NAA L^-1. Therefore, these findings demonstrate that the appropriate combination of P fertilizer and spray NAA is an effective agronomic management strategy for regulating carbon and nitrogen assimilation by maintaining photosynthetic efficiency in plants to increase flax productivity.

Keywords: carbon and nitrogen assimilation; flax; naphthylacetic acid; phosphorus; seed yield.

Grants and funding

This study was supported by the Key Research and Development Projects of Gansu Academy of Agricultural Sciences (2021GAAS20), the National Natural Science Programs of China (31660368), the Major Special Projects of Gansu Province (21ZD4NA022-02), Gansu Intellectual Property Program (21ZSCQ026), Lanzhou Science and Technology Plan Project (2021-1-172), the Youth innovation of Chinese Academy of Agricultural Sciences (Y2023QC31), China Agriculture Research System of MOF and MARA (CARS-17-GW-04) as well as the Technology Innovation of Oil Crops Molecular Breeding and Application (2020GAAS08).