Comparing the Effects of N and P Deficiency on Physiology and Growth for Fast- and Slow-Growing Provenances of Fraxinus mandshurica

Abstract

With the continuous increase in atmospheric carbon dioxide emissions, nitrogen (N) and phosphorus (P) as mineral elements increasingly restrict plant growth. To explore the effect of deficiency of P and N on growth and physiology, Fraxinus mandshurica (hereafter “F. mandshurica”) Rupr. annual seedlings of Wuchang (WC) provenance with fast growth and Dailing (DL) provenance with slow growth were treated with complete nutrition or starvation of N (N-), P (P-) or both elements (NP-). Although P- and N- increased the use efficiency of P (PUE) and N (NUE), respectively, they reduced the leaf area, chlorophyll content and activities of N assimilation enzymes (NR, GS, GOGAT), which decreased the dry weight and P or N amount. The free amino acid content and activities of Phosphoenolpyruvate carboxylase (PEPC) and acid phosphatase enzymes were reduced by N-. The transcript levels of NRT2.1, NRT2.4, NRT2.5, NRT2.7, AVT1, AAP3, NIA2, PHT1-3, PHT1-4 and PHT2-1 in roots were increased, but those of NRT2.1, NRT2.4, NRT2.5, PHT1-3, PHT1-4, PHT2-1 and AAP3 in leaves were reduced by P-. WC was significantly greater than DL under P- in dry weight, C amount, N amount, leaf area, PUE, NUE, which related to greater chlorophyll content, PEPC enzyme activity, N assimilation enzyme activities, and transcript levels of N and P transporter genes in roots and foliage, indicating a greater ability of WC to absorb, transport and utilize N and P under P-. WC was also greater than DL under N- in terms of the above indicators except the transcript levels of N and P assimilation genes, but most of the indicators did not reach a significant level, indicating that WC might be more tolerant to N- than DL, which requires further verification. In summary, WC was identified as a P-efficient provenance, as the growth rate was greater for the genetic type with high than low tolerance to P-.

Dual-nutrient induced stress tolerance in wheat is regulated by nitrogen and phosphorus uptake, assimilation, reutilization, and differential expression of candidate genes

“…So, nitrate assimilation being an energy demanding process, the decrease in activity of enzymes not only under low N but also under low P or low NP is justi ed. A similar reduction in the activity of NR, GS and GOGAT was reported under the combined starvation of both N and P in Fraxinus mandshurica seedlings, a tree species in Northeast China (Zhao et al 2021). The GS and GOGAT enzymes may serve as biochemical markers to identify the dual-nutrient e cient or ine cient genotypes as the relative reduction in their activity was less compared to other N assimilating enzymes.…”

“…Similarly, in mungbean (Vigna radiata), the tolerant accession exhibited increased transcript accumulation of candidate genes enhancing P e ciency and drought tolerance in response to combined stress of low P and drought (Meena et al 2021). Only a few studies have dissected the physiological and molecular response of crops to the combined stress of low N and low P. Zhao et al (2021) studied the response of fast and slow growing annual seedlings of Fraxinus mandshurica under de ciency of N, P and their combined stress. They provided evidence that the fast-growing seedling possessed greater ability to acquire, translocate, and utilize N and P under both N and P de cient conditions compared to the slowgrowing plants.…”

Genome-Wide Identification and Expression Analysis of AMT and NRT Gene Family in Pecan (Carya illinoinensis) Seedlings Revealed a Preference for NH4+-N

“…AtNRT2.5 was a plasma-membrane localized high-affinity NO 3 − transporter protein that mediated NO 3 − acquisition, and reactivation under N deficient conditions [ 27 ], and CiNRT2.5 in this study exhibited the same expression pattern. The transcript levels of NRT2.7 in Fraxinus mandshurica were both upregulated in leaves due to N limitation [ 53 ], whereas CiNRT2.7 in this study was significantly expressed in roots under CK and in leaves under T1, which may be caused by species differences.…”

Function of the NAC1 Gene from <em>Fraxinus mandshurica</em> in Cold Resistance and Growth Promotion in Tobacco

“…Fraxinus mandshurica Rupr., a deciduous tree native to Northeast China and belonging to Fraxinus Linn, is renowned for its robust growth and exceptional cold resistance [1]. Among the distinctive Fraxinus species in the region, it stands out for its remarkable wood quality, which exhibits excellent dryness and suitability for diverse applications.…”