Dear Md. Tofazzal,

Efficient resource management and crop/livestock improvement for evolving better breeds can help to overcome salinity stress. However, such strategies being long drawn and cost intensive. Therefore, there is a need to develop simple and low cost biological methods for salinity stress management, which can be used on short term basis. The following publications discuss the use of microorganisms in this regard. 

1-Saudi J Biol Sci. 2015 Mar; 22(2): 123–131.

Published online 2014 Dec 9. doi:  10.1016/j.sjbs.2014.12.001

PMCID: PMC4336437

Soil salinity: A serious environmental issue and plant growth promoting bacteria as one of the tools for its alleviation

Pooja Shrivastava⁎ and Rajesh Kumar

Author information ► Article notes ► Copyright and License information ►

Go to:

Abstract

Salinity is one of the most brutal environmental factors limiting the productivity of crop plants because most of the crop plants are sensitive to salinity caused by high concentrations of salts in the soil, and the area of land affected by it is increasing day by day. For all important crops, average yields are only a fraction – somewhere between 20% and 50% of record yields; these losses are mostly due to drought and high soil salinity, environmental conditions which will worsen in many regions because of global climate change. A wide range of adaptations and mitigation strategies are required to cope with such impacts. Efficient resource management and crop/livestock improvement for evolving better breeds can help to overcome salinity stress. However, such strategies being long drawn and cost intensive, there is a need to develop simple and low cost biological methods for salinity stress management, which can be used on short term basis. Microorganisms could play a significant role in this respect, if we exploit their unique properties such as tolerance to saline conditions, genetic diversity, synthesis of compatible solutes, production of plant growth promoting hormones, bio-control potential, and their interaction with crop plants.

For more details, see attached file.

2-Salt-tolerant and plant growth-promoting bacteria isolated from Zn/Cd contaminated soil: identification and effect on rice under saline conditions

DOI:

10.1080/17429145.2013.842000

Woranan Nakbanpotea*, Natthawoot Panitlurtumpaia, Aphidech Sangdeea, Narongrit Sakulponea, Pawinee Sirisoma & Apinya Pimthongapages 379-387

Journal of Plant Interactions

Volume 9, Issue 1, 2014

Abstract

The bacteria of PDMCd0501, PDMCd2007, and PDMZnCd2003 were isolated from a Zn/Cd contaminated soil. They were classified as salt-tolerant bacteria in this experiment. The bacteria had indole-3-acetic acids (IAA) production, nitrogen fixation, and phosphate solubilization, under 8% (w/v) NaCl condition. Biochemical test (API 20E) and 16S rDNA sequencing identified PDMCd2007 and PDMCd0501 as Serratia sp. and PDMZnCd2003 was Pseudomonas sp. The effect of Pseudomonas sp. PDMZnCd2003 on the germination and seedlings of Oryza sativa L.cv. RD6 was determined under a salinity of 0–16 dS/m. The salinity levels of 4–16 dS/m affected to decrease germination and seedlings of rice. Comparison between uninoculated and inoculated system, however, Pseudomonas sp. PDMZnCd2003 had a negative impact on the rice growth. This unexpected effect was a case that should be concerned and studied further before application as a plant growth-promoting bacteria (PGPB).

For more details, see attached paper.

3-Microbial amelioration of crop salinity stress

Ian C. Dodd1,* and Francisco Pérez-Alfocea2

J. Exp. Bot. (2012)

doi: 10.1093/jxb/ers033

First published online: March 8, 2012

The use of soil and irrigation water with a high content of soluble salts is a major limiting factor for crop productivity in the semi-arid areas of the world. While important physiological insights about the mechanisms of salt tolerance in plants have been gained, the transfer of such knowledge into crop improvement has been limited. The identification and exploitation of soil microorganisms (especially rhizosphere bacteria and mycorrhizal fungi) that interact with plants by alleviating stress opens new alternatives for a pyramiding strategy against salinity, as well as new approaches to discover new mechanisms involved in stress tolerance. Although these mechanisms are not always well understood, beneficial physiological effects include improved nutrient and water uptake, growth promotion, and alteration of plant hormonal status and metabolism. This review aims to evaluate the beneficial effects of soil biota on the plant response to saline stress, with special reference to phytohormonal signalling mechanisms that interact with key physiological processes to improve plant tolerance to the osmotic and toxic components of salinity. Improved plant nutrition is a quite general beneficial effect and may contribute to the maintenance of homeostasis of toxic ions under saline stress. Furthermore, alteration of crop hormonal status to decrease evolution of the growth-retarding and senescence-inducing hormone ethylene (or its precursor 1-aminocyclopropane-1-carboxylic acid), or to maintain source–sink relations, photosynthesis, and biomass production and allocation (by altering indole-3-acetic acid and cytokinin biosynthesis) seem to be promising target processes for soil biota-improved crop salt tolerance.

For more details, see attached paper.

Hoping this will be helpful,

Rafik

Dear Dr. Rafik Karaman,

Thank you for sharing your thoughts and references. You are really very resourceful and knowledgeable which clearly reflected by your research gate score. Truely exceptional.

Best wishes,

Tofazzal Islam

If you look at salt-tolerant species, I expect that you will find that most of the compartmentalise Na+. Often with Cl- (in most cases but sometimes with HCO3- and others). Australian saltbush has salt glands on the leaves. Mangroves often excrete salt onto waxy leaves (the hydrophobic nature of the wax protects the tissues from osmotic and chemo-toxic effects). Some of these plants run cellular Na ion pumps at very high metabolic cost, but living in high radiation, nutrient rich environments seems to let them profit despite the costs.

Not my area, but something that I've been considering for decades.

best wishes

Dear Dr. Jeffrey Bett Robinson,

Thank you for sharing your thoughts. We are looking at the roles of plant probiotics on salinity tolerance of host plants. We found that many probiotic bacteria enhance salinity tolerance when applied to plants. We need to know the mechanisms of their function.

Regards,

Tofazzal

Hello again. Does the probiotic treatment reduce plant Na+ concentrations (by exclusion or excretion) or does it relieve symptoms by mechanisms within the plant tissues?

Hello again. Does the probiotic treatment reduce plant Na+ concentrations (by exclusion or excretion) or does it relieve symptoms by mechanisms within the plant tissues?

Hello again. Does the probiotic treatment reduce plant Na+ concentrations (by exclusion or excretion) or does it relieve symptoms by mechanisms within the plant tissues?

Sir, You may also check the following article:

Shang, C., Xu, X., Yuan, Z., Wang, Z., Hu, L., Alam, M. A., & Xie, J. (2016). Cloning and differential expression analysis of geranylgeranyl diphosphate synthase gene from Dunaliella parva. Journal of Applied Phycology, 1-9.

Poline are secreted by plant in condition of salinity  or drought stree

Thanks to Dr. Ashraful Alam and Dr. Eddy for comments, information and thoughts. 

Kind regards,

Tofazzal

Md Tofazzal very nice question . Soil salinity imposes highly adverse effects on soil enzymes and  challenges  the plant defense  system  very strongly. However , accumulation in proline in response to soil salinity induced stress is the most common indicator. On the other hand, reduction in soil enzymes , especially urease  and phosphate activity on account of soil salinity is also equally prevalent . Plant enzymes like dismutases, peroxidases, catalases, phenyalanine lyase are some of the plant origin antioxidants associated with soil salinity induced stress , which undergo frequent reorientation  in response to soil salinity . Enclosed below some more pertinent PDFs for further reading .   

Thank you Dr. Anoop KUMAR Srivastava. 

Let me respond to  your quarry in another  way . Infact , soils do not have any enzymatic activity  , and such activity will only be available when there is some substrate for enzymatic activity to take place. Therefore , soils have the enzymatic activity simply because of microbial population , the diversity of which is largely dictated by the nature and properties of the soils.  Soils  have been reported to display  display some enzymatic activity upto EC of as high as 70 dS/m. Let us try to isolate some salinity tolerant microbes from such soils ,  develop a consortium of such salinity tolerant microbes to tailor the microbial activity  in saline soils and ensure better enzymatic activity as an indicator  microbial activity . Find below a PDF for further reading .