Table 5 Comparative analysis between enriched biological processes from RNA sequencing and differentially abundant metabolites in Brassica napus under N, P and K deprivations

N-R

Aromatic amino acid family catabolism*

-

D-( +)-Tryptophan

Tricarboxylic acid biosynthesis*

DL-Malic acid; Succinic acid

-

Oxazole or thiazole biosynthesis*

Epigoitrin

-

Carbohydrate derivative catabolism

Nystose;

D-( +)-Maltose;

D-Gluconic acid

Isomaltose;

Acetaminophen glucuronide;

Mucic acid

Cinnamic acid biosynthesis

-

Trans-cinnamic acid;

Methyl cinnamate;

Cinnamic Acid

Glucosamine-containing compound metabolism

-

UDP-N-acetylglucosamine

Glutamine family amino acid metabolism

-

DL-Glutamine;

D-(-)-Glutamine

Nicotianamine metabolism

-

Nicotianamine

P-R

Aromatic amino acid family catabolism*

-

Alanyltyrosine;

gamma-Glutamyltyrosine;

L-Tyrosine; L-Phenylalanine;

N-Acetylphenylalanine

Tricarboxylic acid biosynthesis*

Methylenesuccinic acid;

2,2-Dimethylsuccinic acid;

2-Isopropylmalic acid

Citric acid;

D-threo-Isocitric acid

Oxazole or thiazole biosynthesis*

2-Mercaptobenzothiazole

N-(4-methoxy-1-methyl-1H-indazol-3-yl)-5-methyl-3-isoxazolecarboxamide

Sterol biosynthesis*

Estrone sulfate

-

Aminoglycan catabolism

-

Glucosamine

P-R

Tryptophan catabolism

5-Hydroxytryptophan

-

Disaccharide biosynthesis

Sucrose;

D-( +)-Maltose

-

Oligosaccharide biosynthesis

Stachyose;

D-Raffinose;

Nystose

-

Fructose 6-phosphate metabolism

D-Mannose 6-phosphate

-

Trehalose biosynthesis

α,α-Trehalose

-

Indole-containing compound catabolism

Indole-3-carboxylic acid;

3-Indolepropionic acid

6-Hydroxymelatonin

K-R

*Sterol biosynthesis

Stigmasterol; Vitamin D2; Ergocalciferol

-

N-S

Response to auxin stimulus

Indole-3-carboxaldehyde

-

Response to hormone stimulus

Indole-3-carboxaldehyde;

Abscisic Acid

Gibberellin A4

Aspartate family amino acid metabolism

-

Asparagine

P-S

Indole-containing compound catabolism

Tryptophol; Methyl indole-3-acetate;

Indole-3-carboxaldehyde

Indole-3-acetic acid;

Indole-3-carboxylic acid;

3-Indoleacetonitrile;

L-Tryptophan;

2-(1H-indol-3-yl)acetic acid; Indole

Tryptophan catabolism

L-Tryptophan

Aromatic compound biosynthesis

2-Hydroxyphenylalanine;

N-Acetylphenylalanine; L-Tryptophan

-

K-S

Response to auxin stimulus

Indole-3-acetic acid; Indole-3-acetamide;

3-Indolepropionic acid

-