TABLE 9.

Upregulation of stress-responsive genes by PGPR under drought conditions.

Soil microbe/Strain	Plant species	Effect under drought	References
Bacillus amyloliquefaciens 5113	Wheat	Upregulation of stress related genes APX1, SAMS1, and HSP17.8	Kasim et al., 2013
P. chloroaphis O6	Arabidopsis	Transcription of JA biosynthesis (VSP1, pdf-1.2) and salicylic acid regulated gene (PR-1)	Cho et al., 2013
Bacillus licheniformis K11	Pepper	Inoculation increased the expression of stress responsive genes Cadhn, VA, sHSP, and CaPR-10	Lim and Kim, 2013
Azospirillum brasilense SP-7, H. seropedicae Z-152	Maize	Upregulation of ABA biosynthesis gene ZmVP14	Curá et al., 2017
P. putida	Chickpea	Activation of ethylene, salicylic acid (PR1) and jasmonate (MYC2) biosynthesis genes under drought	Tiwari et al., 2016
B. subtilis LDR2	Wheat	Upregulate the expression of TaCTR1/TaDREB2 TFs under drought stress	Barnawal et al., 2017
P. flourescens Pf1	Rice	The activations of ABA mediated signaling pathway genes like bZIP1, AP2-EREBP, and Hsp20	Saakre et al., 2017
B. subtilis strain SYST2	Tomato	Enhanced the expression of auxin (SlIAA1. SlIAA3), gibberellin (GA20ox-1), CK (SlCKX1), expansion (Exp2, Exp9. Exp 18), and ethylene (ACO1) biosynthesis genes	Tahir et al., 2017
Bacillus amyloliquefaciens FZB42	Arabidopsis	Expression of drought defense related genes such as RD29A, RD17, ERD1, and LEA14	Lu et al., 2018
Bacillus amyloliquefaciens	Tomato	Elevated expression of stress responsive genes, i.e., lea, tdi65, and ltpg2, increased in	Wang et al., 2019
Streptomyces sp.	Tomato	Modulate the expression of TF ERF1 and WRKY70 under drought stress	Abbasi et al., 2020
F. crocinum HYN0056	Arabidopsis	Upregulation of drought responsive genes RD29A and RAB18	Kim et al., 2020
Trichoderma sp. Pseudomonas sp.	Rice	Over expression of water permeability (OSPiP), drought adaptation (DHN) and dehuderation genes (DREB)	Singh et al., 2020