Abstract
Root-tissue colonizing bacteria demonstrated with multiple PGP traits from sorghum plants were identified as Ochrobactrum sp. EB-165, Microbacterium sp. EB-65, Enterobacter sp. EB-14 and Enterobacter cloacae strain EB-48 on the basis of 16S rRNA gene sequencing. Here, the in vivo experiments using ½-MS media and ½-MS media + 15% PEG 8000 (for inducing drought stress) indicated stress tolerance imparting ability of these rhizobacterial endophytes in a non-stay green and senescent genotype (R-16) of sorghum. In the experiment with sterile soilrite mix base, seed bacterization with these isolates showed improved plant growth specifically the roots, in terms of root length (~ 44.2 to 50.8% over controls), root dry weight (~ 91.3 to 99.8% over controls) and root surface area (~ 1 to 1.5 fold over controls) under drought stress. Rhizobacterial endophytes were successful, not only in providing better cellular osmotic adjustment in leaves (≥ 1-fold increase in proline accumulation over controls), but favorable physiological responses like Relative Water Content (RWC) and cell Membrane Stability Index (MSI) in the inoculated plants during the drought stress induction. Up-regulation of drought responsive genes like sbP5CS2 and sbP5CS1 was observed in these endophytes-treated plants as compared to untreated control and Escherichia coli DH5α (negative control)-treated plants. Interestingly, the stress imparting traits of rhizobacterial endophytes, including up-regulation of specific genes, were observed during sorghum seedling growth only under drought stresses. The results of this study lead to the conclusion that the potential endophytic rhizobacterial interactions can contribute to plant growth promotion as well as induced stress tolerance in sorghum.
Similar content being viewed by others
References
Ahanger MA, Agarwal RM (2017) Potassium up-regulates antioxidant metabolism and alleviates growth inhibition under water and osmotic stress in wheat (Triticum aestivum L). Protoplasma 254:1471–1486
Ahanger MA, Tyagi SR, Wani MR, Ahmad P (2014) Drought tolerance: role of organic osmolytes, growth regulators, and mineral nutrients. In: Ahmad P, Wani M (eds) physiological mechanisms and adaptation strategies in plants under changing environment. Springer, New York, pp 25–55
Ahanger MA, Agarwal RM, Tomar NS, Shrivastava M (2015) Potassium induces positive changes in nitrogen metabolism and antioxidant system of oat (Avena sativa L. cultivar Kent). J Plant Int 10:211–223
Ahanger MA, Tittal M, Mir RA, Agarwal RM (2017) Alleviation of water and osmotic stress-induced changes in nitrogen metabolizing enzymes in Triticum aestivum L. cultivars by potassium. Protoplasma 254:1953–1963
Ali SZ, Sandhya V, Grover M, Kishore N, Rao LV, Venkateswarlu B (2009) Pseudomonas sp. strain AKM-P6 enhances tolerance of sorghum seedlings to elevated temperatures. Biol Fert Soils 46:45–55
Ansari SA, Kumar P, Gupta BN (1995) Root surface measurements based on adsorption and desorption of nitrite. Plant Soil 175:133–137
Barka EA, Nowak J, Clément C (2006) Enhancement of chilling resistance of inoculated grapevine plantlets with a plant growth-promoting rhizobacterium Burkholderia phytofirmans strain PsJN. Appl Environ Microbiol 72:7246–7252
Bates L, Waldren RP, Teare ID (1973) Rapid determination of free proline for water-stress studies. Plant Soil 39:205–207
Berg G (2009) Plant–microbe interactions promoting plant growth and health: perspectives for controlled use of microorganisms in agriculture. Appl Microbiol Biotech 84:11–18
Budi SW, van Tuinen D, Martinotti G, Gianinazzi S (1999) Isolation from the Sorghum bicolor mycorrhizosphere of a bacterium compatible with arbuscular mycorrhiza development and antagonistic towards soil borne fungal pathogens. Appl Environ Microbiol 65:5148–5550
Charles TC, Nester EW (1993) A chromosomally encoded two-component sensory transduction system is required for virulence of Agrobacterium tumefaciens. J Bacteriol 175:6614–6625
Compant S, Clément C, Sessitsch A (2010) Plant growth-promoting bacteria in the rhizo-and endosphere of plants: their role, colonization, mechanisms involved and prospects for utilization. Soil Biol Biochem 42:669–678
Cornic G (1994) Drought stress and high light effects on leaf photosynthesis. In: Baker NR, Bowyer JR (eds) Photo inhibition of Photosynthesis: from molecular mechanisms to the field. BIOS Oxford publications, Oxford, pp 297–313
Dicko MH, Gruppen H, Traoré AS, Voragen AG, van Berkel WJ (2006) Sorghum grain as human food in Africa: relevance of starch content and amylase activities. Afr J Biotechnol 5:384–395
Dimkpa C, Weinand T, Asch F (2009) Plant–rhizobacteria interactions alleviate abiotic stress conditions. Plant Cell Environ 32:1682–1694
Fabro G, Kovacs I, Pavet V, Szabados L, Alvarez ME (2004) Proline accumulation and AtP5CS2 gene activation are induced by plant–pathogen incompatible interactions in Arabidopsis. Mol Plant Microbe Interact 17:343–350
Funnell-Harris DL, Sattler SE, Pedersen JF (2013) Characterization of fluorescent Pseudomonas spp. associated with roots and soil of two sorghum genotypes. Eur J Plant Pathol 136:469–481
George P, Gupta A, Gopal M, Thomas L, Thomas GV (2013) Multifarious beneficial traits and plant growth promoting potential of Serratia marcescens KiSII and Enterobacter sp. RNF 267 isolated from the rhizosphere of coconut palms (Cocos nucifera L.). World J Microbiol Biotechnol 29:109–117
Govindasamy V, Senthilkumar M, Magheshwaran V, Kumar U, Bose P, Sharma V, Annapurna K (2011) Bacillus and Paenibacillus spp.: potential PGPR for sustainable agriculture. In: Maheshwari DK (ed) Plant growth and health promoting bacteria. Microbiology monographs, vol 18. Springer, Berlin, pp 333–364
Govindasamy V, Franco CMM, Gupta VV (2014) Endophytic actinobacteria: diversity and ecology. In: Verma VC, Gange A (eds) Advances in endophytic research. Springer, Berlin, pp 27–59
Govindasamy V, Raina SK, George P, Kumar M, Rane J, Minhas PS, Vittal KPR (2017) Functional and phylogenetic diversity of cultivable rhizobacterial endophytes of sorghum [Sorghum bicolor (L.) Moench]. Antonie Van Leeuwenhoek 110:925–943
Govindasamy V, George P, Raina SK, Kumar M, Rane J, Annapurna K (2018) Plant-associated microbial interactions in the soil environment: role of endophytes in imparting abiotic stress tolerance to crops. In: Bal SK, Mukherjee J, Choudhury BU, Dhawan AK (eds) Advances in crop environment interaction. Springer, GmbH, Heidelberg, Germany, pp 245–284
Hirsch PR, Mauchline TH (2012) Who’s who in the plant root microbiome? Nat Biotechnol 30:961–962
Hmida-Sayari A, Gargouri-Bouzid R, Bidani A, Jaoua L, Savoure A, Jaoua S (2005) Over expression of D1-pyrroline-5-carboxylate synthase increases proline production and confers salt tolerance in transgenic potato plants. Plant Sci 169:746–750
Kloepper JW, Ryu CM, Zhang S (2004) Induced systemic resistance and promotion of plant growth by Bacillus spp. Phytopathology 94:1259–1266
Lane DJ (1991) 16S/23S rRNA sequencing. In: Stackebrandt E, Goodfellow M (eds) Nucleic acid techniques in bacterial systematics. Wiley Publications, Chichester, pp 115–176
Marasco R, Rolli E, Ettoumi B, Vigani G, Mapelli F, Borin S, Ayman FA, El-Behairy UA, Sorlini C, Cherif A, Zocchi G, Daffonchio DA (2012) Drought resistance-promoting microbiome is selected by root system under desert farming. PLoS One 7(10):e48479. https://doi.org/10.1371/journal.pone.0048479
Nayak SN, Balaji J, Upadhyaya HD, Hash CT, Kishor PK, Chattopadhyay D, Rodriquez LM, Blair MW, Baum M, McNally K, This D (2009) Isolation and sequence analysis of DREB2A homologues in three cereal and two legume species. Plant Sci 177(5):460–467
Pedersen WL, Chakrabarty K, Klucas RV, Vidaver AK (1978) Nitrogen fixation (acetylene reduction) associated with roots of winter wheat and sorghum in Nebraska. Appl Environ Microbiol 35:129–135
Pieterse CMJ, Zamioudis C, Berendsen RL, Weller DM, Van Wees SCM, Bakker PAHM (2014) Induced systemic resistance by beneficial microbes. Annu Rev Phytopathol 52:347–375
Rahimi A, Hosseini MS, Pooryoosef M, Fateh I (2010) Variation of leaf water potential, relative water content and SPAD under gradual drought stress and stress recovery in two medicinal species of Plantago ovate and P. psyllium. Plant Ecophysiol 2:53–60
Reinhold-Hurek B, Hurek T (2011) Living inside plants: bacterial endophytes. Curr Opin Plant Biol 14:435–443
Rosenblueth M, Martínez-Romero E (2006) Bacterial endophytes and their interactions with hosts. Mol Plant Microbe Interact 19:827–837
Sairam RK (1994) Effect of moisture stress on physiological activities of two contrasting wheat genotypes. Indian J Exp Biol 3:584–593
Sambrook J, Russell RW (2001) Molecular cloning: a laboratory manual, 3rd edn. Cold Spring Harbor Laboratory Press, New York
Senthilkumar M, Swarnalakshmi K, Govindasamy V, Lee YK, Annapurna K (2009) Biocontrol potential of soybean bacterial endophytes against charcoal rot fungus, Rhizoctonia bataticola. Curr Microbiol 58(4):288–293
Shahid MA, Balal RM, Pervez MA, Abbas T, Ashfaq M, Ghazanfar U, Afzal M, Rashid A, Garcia-Sanchez F, Mattson NS (2012) Differential response of pea (Pisum sativum L.) genotypes to salt stress in relation to the growth, physiological attributes, antioxidant activity and organic solutes. AJCS 6:828–838
Sherameti I, Tripathi S, Varma A, Oelmüller R (2008) The root-colonizing endophyte Piriformospora indica confers drought tolerance in Arabidopsis by stimulating the expression of drought stress-related genes in leaves. Mol Plant Microbe Interact 21(6):799–807
Singh B, Ahuja S, Singhal RK, Babu VP (2013) Effect of gamma radiation on wheat plant growth due to impact on gas exchange characteristics and mineral nutrient uptake and utilization. J Radioanal Nuclear Chem 298:249–257
Su M, Li XF, Ma XY, Peng XJ, Zhao AG, Cheng LQ, Chen SY, Liu GS (2011) Cloning two P5CS genes from bioenergy sorghum and their expression profiles under abiotic stresses and MeJA treatment. Plant Sci 181(6):652–659
Sziderics AH, Rasche F, Trognitz F, Sessitsch A, Wilhelm E (2007) Bacterial endophytes contribute to abiotic stress adaptation in pepper plants (Capsicum annuum L.). Can J Microbiol 53:1195–1202
Yang J, Kloepper JW, Ryu CM (2009) Rhizosphere bacteria help plants tolerate abiotic stress. Trends Plant Sci 14:1–4
Zhang C, Bian M, Yu H, Liu Q, Yang Z (2011) Identification of alkaline stress-responsive genes of CBL family in sweet sorghum (Sorghum bicolor L.). Plant Physiol Biochem 49(11):1306–1312
Zinniel DK, Lambrecht P, Harris NB, Feng Z, Kuczmarski D, Higley P, Ishimaru CA, Arunakumari A, Barletta RG, Vidaver AK (2002) Isolation and characterization of endophytic colonizing bacteria from agronomic crops and prairie plants. Appl Environ Microbiol 68:2198–2208
Acknowledgements
The first author expresses his gratitude to Dr. H S Talwar, ICAR-Indian Institute of Millets Research, Hyderabad, India for providing seeds of sorghum stay green and non-stay green genotypes. Thanks are due to Dr. S. V. Ramesh, ICAR-CPCRI, Kasaragod, India and Dr. P. Panneerselvam, ICAR-NRRI, Cuttack, India for critically going through the manuscript. We are grateful to the Director, ICAR-National Institute of Abiotic Stress Management, Baramati for providing necessary laboratory facilities. The authors are also thankful to the Indian Council of Agricultural Research, New Delhi for funding this study (Project Ref. No.: IXX08578).
Author information
Authors and Affiliations
Contributions
VG conceived and designed the study, performed the experiments and data analysis, and wrote the manuscript. PG maintained the endophyte seed stocks, grew plants, helped in data recording, growth analysis of plant samples and wrote the manuscript. LA grew plants, helped in data recording and molecular analysis of plant samples. MK and SKR helped in physiological measurements and data analysis. KA helped in editing the manuscript. JR supervised the study and revised the manuscript. PSM coordinated the project. All authors read and approved the final manuscript.
Corresponding author
Ethics declarations
Conflict of interest
The authors declare that they do not have any conflict of interest.
Research involving human participants and/or animals
This article does not contain any studies with human participants or animals performed by any of the authors.
Rights and permissions
About this article
Cite this article
Govindasamy, V., George, P., Kumar, M. et al. Multi-trait PGP rhizobacterial endophytes alleviate drought stress in a senescent genotype of sorghum [Sorghum bicolor (L.) Moench]. 3 Biotech 10, 13 (2020). https://doi.org/10.1007/s13205-019-2001-4
Received:
Accepted:
Published:
DOI: https://doi.org/10.1007/s13205-019-2001-4