Physiological and Transcriptional Characteristics of Banana Seedlings in Response to Nitrogen Deficiency Stress

Abstract

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.

Investigation of morpho-physiolgical traits and gene expression in barley under nitrogen deficiency

“…Based on the previous studies, root development might be related to the ND-induced signaling cascade 21 , 22 . Root growth was stimulated by both the increased root uptake area and reduced nutrient demand in shoots 23 . In C. odorata plants experiencing nitrogen deficiency, metabolic resources were allocated preferentially to root system growth 24 .…”

Special Issue “Horticultural Plant Nutrition, Fertilization and Soil Management”

“…In turn, Zhao et al (2024) delve into the physiological and molecular mechanisms underlying nitrogen deficiency stress in banana seedlings. Their research provides valuable information on the transcriptional regulatory mechanisms governing banana responses to low-nitrogen stress, facilitating the development of new varieties with improved nutrient utilization capacity.…”