Physiological and Transcriptional Characteristics of Banana Seedlings in Response to Nitrogen Deficiency Stress
Lei Zhao,
Bingyu Cai,
Xiaohan Zhang,
Bencheng Zhang,
Junting Feng,
Dengbo Zhou,
Yufeng Chen,
Miaoyi Zhang,
Dengfeng Qi,
Wei Wang,
Jianghui Xie,
Yongzan Wei
Affiliations
Lei Zhao
State Key Laboratory of Biological Breeding of Tropical Crops, School of Tropical Agriculture and Forestry, Hainan University, Sanya 570228, China
Bingyu Cai
State Key Laboratory of Biological Breeding of Tropical Crops, Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Sciences, Haikou 571101, China
Xiaohan Zhang
Sanya Research Academy, Chinese Academy of Tropical Agriculture Science, Sanya 572019, China
Bencheng Zhang
State Key Laboratory of Biological Breeding of Tropical Crops, School of Tropical Agriculture and Forestry, Hainan University, Sanya 570228, China
Junting Feng
State Key Laboratory of Biological Breeding of Tropical Crops, Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Sciences, Haikou 571101, China
Dengbo Zhou
State Key Laboratory of Biological Breeding of Tropical Crops, Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Sciences, Haikou 571101, China
Yufeng Chen
State Key Laboratory of Biological Breeding of Tropical Crops, Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Sciences, Haikou 571101, China
Miaoyi Zhang
State Key Laboratory of Biological Breeding of Tropical Crops, Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Sciences, Haikou 571101, China
Dengfeng Qi
State Key Laboratory of Biological Breeding of Tropical Crops, Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Sciences, Haikou 571101, China
Wei Wang
State Key Laboratory of Biological Breeding of Tropical Crops, Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Sciences, Haikou 571101, China
Jianghui Xie
State Key Laboratory of Biological Breeding of Tropical Crops, Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Sciences, Haikou 571101, China
Yongzan Wei
State Key Laboratory of Biological Breeding of Tropical Crops, Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Sciences, Haikou 571101, China
Nitrogen is a crucial element for the growth and development of plants, directly affecting crop growth and yield. To investigate the physiological and molecular mechanism of nitrogen-deficiency stress, we conducted an investigation into the effects of different nitrogen levels on the growth, photosynthetic characteristics, and gene transcription levels of banana seedlings. Compared with the control group with normal nitrogen levels (NN), the height of plants receiving Reduced-N (NR), Low-N (LN), and N-Free (NF) treatments was decreased by 0.45 cm, 2.5 cm, and 3.25 cm, respectively. Their dry weight was reduced by 1.63 g, 2.99 g, and 2.88 g, respectively. Conversely, the dry weight of the underground plant part in the LN and NF treatment groups exhibited an increase of 0.13 g and 0.16 g, respectively. Regarding photosynthetic characteristics, the Specialty Products Agricultural Division (SPAD) values of the NR, LN, and NF treatments showed reductions of 15.5%, 30.4%, and 35.9%, respectively, compared with those of the control treatments. The values of maximum photosynthetic efficiency (Fv/Fm), actual photosynthetic efficiency (Y(Ⅱ)), and relative electron transfer (ETR) of the banana seedlings decreased to different degrees after NR, LN, and NF treatment, and their values were positively correlated with N levels. Gene transcription analysis showed that N transport-related proteins, including NRT1.7, NRT2.3a, NRT2.3b, and NRT2.5, were significantly up-regulated to increase the nitrogen absorption capacity of plant roots. On the other hand, various transcription factors including GRAS, MYB, and WRKY were notably up-regulated, facilitating root growth and the expanding root absorption area, thereby enhancing nitrogen uptake. Furthermore, genes associated with endogenous hormone metabolic pathways such as gibberellin (GA), strigolactone (SL), and brassinosteroids (BR) were activated in banana plants subjected to low nitrogen stress, enhancing the plant’s ability to adapt to nitrogen-deficient conditions. These findings offer valuable insights into understanding the transcriptional regulatory mechanisms governing banana responses to low nitrogen stress and breeding new varieties with improved nutrient utilization.
