Evaluation of the Effect of Plant Growth Promoting Endophytic Bacteria from Pinellia ternata Using an Efficient Organic Silica Hybrid Monolithic Column

This study aims to investigate the plant growth promoting bacteria (PGPB) in the medicinal plant Pinellia ternata (P. ternata), and evaluate the effect of PGPB on the growth and alkaloid content of P. ternata. Bacteria were isolated from P. ternate, and 16S rRNA gene sequencing of partial isolates was carried out. 23 kinds of representative bacteria were classified into 7 genera: Acinetobacter, Bacillus, Enterobacter, Pseudomonas, Kosakonia, Rhizobium and Stenotrophomonas. The results of the plant growth promotion screening showed that 23 strains could produce different levels of Indole-3-acetic acid (IAA), 1-aminocyclopropane-1-carboxylicacid deaminase (ACC), biofilm and certain enzymes. Potential PGPB were selected to evaluate their abilities to promote the growth of wheat. The results indicated that strain PtB01 (Rhizobium nepotum) and PtB24 (Bacillus methylotrophicus) significantly promoted the growth of the wheat seedlings. These two strains and their co-culture group were inoculated on P. ternata aseptic seedlings. It was found that these strains increased shoot length by 194%, root length by 307%, leaf area by 232%, fresh weight by 231%, dry weight by 165%, and the number of fibrous roots by 200%. We also designed a novel organic silica hybrid monolithic column through silicon dioxide modification and tested the influence of two strains on the alkaloid in P. ternata aseptic seedlings. The result showed that the content of alkaloid was increased by 140% after inoculation PGPB in P. ternata. PGPB from the medicinal plant P. ternata promoted the growth of the host plant and influenced the alkaloid content of P. ternata.