Genome-wide identification of the amino acid permease genes and molecular characterization of their transcriptional responses to various nutrient stresses in allotetraploid rapeseed

Abstract

Background: Nitrogen (N), referred to as a "life element", is a macronutrient essential for optimal plant growth and yield production. Amino acid (AA) permease (AAP) genes play pivotal roles in root import, long-distance translocation, remobilization of organic amide-N from source organs to sinks, and other environmental stress responses. However, few systematic analyses of AAPs have been reported in Brassica napus so far. Results: In this study, we identified a total of 34 full-length AAP genes representing eight subgroups (AAP1-8) from the allotetraploid rapeseed genome (A n A n C n C n , 2n = 4x = 38). Great differences in the homolog number among the BnaAAP subgroups might indicate their significant differential roles in the growth and development of rapeseed plants. The BnaAAPs were phylogenetically divided into three evolutionary clades, and the members in the same subgroups had similar physiochemical characteristics, gene/protein structures, and conserved AA transport motifs. Darwin's evolutionary analysis suggested that BnaAAPs were subjected to strong purifying selection pressure. Ciselement analysis showed potential differential transcriptional regulation of AAPs between the model Arabidopsis and B. napus. Differential expression of BnaAAPs under nitrate limitation, ammonium excess, phosphate shortage, boron deficiency, cadmium toxicity, and salt stress conditions indicated their potential involvement in diverse nutrient stress responses. Conclusions: The genome-wide identification of BnaAAPs will provide a comprehensive insight into their family evolution and AAP-mediated AA transport under diverse abiotic stresses. The molecular characterization of core AAPs can provide elite gene resources and contribute to the genetic improvement of crop stress resistance through the modulation of AA transport.

Genome-wide identification of Brassicaceae B-BOX genes and molecular characterization of their transcriptional responses to various nutrient stresses in allotetraploid rapeseed

“…The expression patterns of BnaBBXs were investigated to identify their functions in regulating various nutrient stresses. B, N, P, and K were nutrients required for plant growth; they had essential roles in diverse plant physiological pathways and oxidative stresses [ 33 , 35 , 36 ]. In the roots and shoots, 21 BnaBBXs were upregulated or downregulated by B limitation, and 9 genes were affected by B toxicity (Fig.…”

“…The Cd- and salt-treated 17-day-old Zhongshuang 11 seedlings were, respectively, grown in a solution containing 10 μM CdCl 2 for 12 h and 200 mM NaCl for 1 d. The seedlings in the control groups were cultivated in a normal solution for appropriate times based on the aforementioned treatments. Comparative transcriptomes were performed using roots and shoots from control and stress-treated plants in previous studies [ 27 , 33 , 35 , 41 , 52 , 53 ]; the transcriptome data can be found in published studies. Differentially expressed genes are defined as those with P value < 0.05, false-discovery rate less than 0.05, and |log 2 (fold-change)| ≥ 1.…”

“…In Brassicaceae, several nutrient-related gene families have been identified, such as amino acid ( AA ) permease ( AAP ) and aquaporin ( AQP ) [ 32 , 33 ]. However, the information about BBX genes is limited and their roles in nutrient regulation are not identified.…”

Manipulating Amino Acid Metabolism to Improve Crop Nitrogen Use Efficiency for a Sustainable Agriculture

“…It can be seen above that the potential of AAP and UMAMIT genes for improving NUE in N-limiting conditions has not been fully investigated among crops while the recent genomewide identification of AAP genes and their regulation during various stresses in many crops will definitely provide interesting targets for the future improvement of crop NUE (Ma et al, 2016;Wan et al, 2017;Qu et al, 2019;Duan et al, 2020;Zhou et al, 2020).…”

Overdominance at the Gene Expression Level Plays a Critical Role in the Hybrid Root Growth of Brassica napus

“…This implies that roots could be the perfect organ to investigate the genetic basis of B. napus heterosis at the early growth stage. Several efforts have been made to expose the molecular system of root growth heterosis during the vegetative stage [15][16][17]. Moreover, previous studies have shown that cotton heterosis can be linked to vegetative heterosis at the seedling stage [18].…”