UHPLC-MS/MS and QRT-PCR profiling of PGP agents and Rhizobium spp . of induced phytohormones for growth promotion in mungbean (var. Co4 )

Chaitanya S Mogal; Vanrajsinh H Solanki; Rohan V Kansara; Sanjay Jha; Susheel Singh; Vipulkumar B Parekh; B K Rajkumar

doi:10.1016/j.heliyon.2022.e09532

UHPLC-MS/MS and QRT-PCR profiling of PGP agents and Rhizobium spp . of induced phytohormones for growth promotion in mungbean (var. Co4 )

Heliyon. 2022 May 26;8(5):e09532. doi: 10.1016/j.heliyon.2022.e09532. eCollection 2022 May.

Authors

Chaitanya S Mogal¹, Vanrajsinh H Solanki², Rohan V Kansara², Sanjay Jha³, Susheel Singh², Vipulkumar B Parekh⁴, B K Rajkumar⁵

Affiliations

¹ Department of Plant Molecular Biology and Biotechnology, Navsari Agricultural University, Navsari, 396450, Gujarat, India.
² Food Quality Testing Laboratory, N. M. College of Agriculture, Navsari Agricultural University, Navsari, 396450, Gujarat, India.
³ ASPEE Shakilam Biotechnology Institute, Navsari Agricultural University, Surat, 395007, Gujarat, India.
⁴ Department of Basic Science and Humanities, ACHF, Navsari Agricultural University, Navsari, 396450, Gujarat, India.
⁵ Main Cotton Research Station, Navsari Agricultural University, Surat, 395007, Gujarat, India.

Abstract

In present study, five potential strains with different plant growth promotion (PGP) characteristics were used. By considering various PGP properties of different bacterial strains, several treatments based on various combinations were developed and studied on mungbean (var. Co4). The quantification of the phytohormones was performed on ultrahigh-performance liquid chromatograph coupled to heated electrospray ionization tandem mass spectrometry (UHPLC/HESI-MS/MS). Indole 3-acetic acid (IAA) and Indole 3-butyric acid (IBA) were quantified in positive ionization mode while Gibberellic acid (GA₃) and salicylic acid (SA) were quantified in negative ionization mode. Among all the treatments two penta combinations of consortia 1 (Rhizobium + Azospirillum + Pseudomonas + Bacillus spp. + Bacillus licheniformis) and consortia 2 (Rhizobium + Azotobacter + Pseudomonas + Bacillus spp. + Bacillus licheniformis) were found most effective. Higher amount of IAA (1.043 μg g^-1), IBA (0.036 μg g^-1), GA₃ (1.999 μg g^-1) and SA (0.098 μg g^-1) Fresh weight (FW) were found in treated adolescent root tissues of consortia 2 as compared to consortia 1. Moreover, transcriptional level of the plant hormones were 2-4 fold higher in the relative gene expression study of three genes: ARF (Auxin responsive factors), ERF-IF (Ethylene-responsive Initiation Factors) and GAI (Gibberellic-Acid Insensitive) in consortia 2, on the 15^th, 30^th and 45^th day using quantitative real time-Polymerase chain reaction (qRT-PCR). Furthermore, Yield attributing characters like, the number of nodules plant^-1, number of pods plant^-1, weight of nodule and seed yield plant^-1 were also increased as compared to the control. As a result, the current research elucidated that penta combinations consortium of Rhizobium sp. and rhizobacteria can be developed as a single delivery system biofertilizer for enhancing mungbean productivity.

Keywords: ARF gene; ERF-IF gene; GAI gene; Mungbean; PGPR consortia; Rhizobium spp.; UHPLC-MS/MS; qRT-PCR.