Systematic Analysis of Alkaline/Neutral Invertase Genes Reveals the Involvement of Smi-miR399 in Regulation of SmNINV3 and SmNINV4 in Salvia miltiorrhiza

Abstract

Alkaline/neutral invertases (NINVs), which irreversibly catalyze the hydrolysis of sucrose into fructose and glucose, play crucial roles in carbohydrate metabolism and plant development. Comprehensive insights into NINV genes are lacking in Salvia miltiorrhiza, a well-known traditional Chinese medicinal (TCM) plant with significant medicinal and economic value. Through genome-wide prediction, nine putative SmNINV genes, termed SmNINV1-SmNINV9, were identified. Integrated analysis of gene structures, sequence features, conserved domains, conserved motifs and phylogenetic trees revealed the conservation and divergence of SmNINVs. The identified SmNINVs were differentially expressed in roots, stems, leaves, flowers, and different root tissues. They also responded to drought, salicylic acid, yeast extract, and methyl jasmonate treatments. More importantly, computational prediction and experimental validation showed that SmNINV3 and SmNINV4 were targets of Smi-miR399, a conserved miRNA previously shown to affect Pi uptake and translocation through the cleavage of PHOSPHATE2 (PHO2). Consistently, analysis of 43 NINV genes and 26 miR399 sequences from Arabidopsis thaliana, Populus trichocarpa, Manihot esculenta, and Solanum lycopersicum showed that various AtNINV, PtNINV, MeNINV, and SlNINV genes were regulated by miR399. It indicates that the miR399-NINV module exists widely in plants. Furthermore, Smi-miR399 also cleaved SmPHO2 transcripts in S. miltiorrhiza, suggesting the complexity of NINVs, PHO2, and miR399 networks.

Integrated Transcriptome and Targeted Metabolite Analysis Reveal miRNA-mRNA Networks in Low-Light-Induced Lotus Flower Bud Abortion

“…As a target gene of miR399a_3, the β-fructofuranosidase gene (XM_010260719.2) was significantly down-regulated in the aborting flower buds with the increased expression level of miR399a_3 ( Tables S3–S5 ). Recently, miR399 has been shown to be involved in the regulation of alkaline/neutral invertase ( NINV ) genes in Salvia Miltiorrhiza [ 37 ]. Meanwhile, as the inhibitor of acid invertase, cell wall/vacuolar inhibitor of fructosidase 2-like was also down-regulated in the aborting flower buds and targeted by novel_mir13 ( Tables S3–S5 ).…”

Genome-wide identification and expression pattern of alkaline/neutral invertase gene family inDendrobium catenatum

“…The DcNI2 and DcNI7 expression levels were very low or undetectable. In mature primary wheat leaves, the Ta-A-Inv gene is expressed under cold stress [42]. The expression of DcNI1, DcNI3, DcNI5, DcNI8 and DcNI9 was significantly down-regulated when induced by cold and low temperature, which may be due to plants blocking the decomposition of sucrose to resist the adverse cold environment.…”

“…It is speculated that there are JA-responsive cis-acting elements in these two genes. According to reports, the expression of NI genes SmNINV8 and SmNINV9 in Salvia miltiorrhiza also was up-regulated by MeJA induction [42], while under drought stress conditions, there was no significant change in gene expression after dehydration and rewatering. It is possible that the DcNI genes may not be involved in the regulation under drought conditions.…”

Genome-Wide Identification and Functional Analysis of Salvia miltiorrhiza MicroRNAs Reveal the Negative Regulatory Role of Smi-miR159a in Phenolic Acid Biosynthesis

“…For instance, smi-miR12112, a lineage-specific miRNA family, could be involved in phenolic compound metabolism through regulating polyphenol oxidase genes (SmPPOs) [32]. Smi-miR399 could be involved in secondary metabolism through regulating alkaline/neutral invertase genes (SmNINVs) [33]. Overexpression of smi-miR396b in S. miltiorrhiza hairy roots led to the repression of salvianolic acid biosynthesis and to the enhancement of tanshinone production through regulating the expression of SmGRF, SmHDT1, and Sm-MYB37/4 genes [34].…”