Potential of Purple Non-Sulfur Bacteria in Sustainably Enhancing the Agronomic and Physiological Performances of Rice

Abstract

Cereal grains and tubers are among the highly consumed staple foods globally; however, due to unfavorable weather conditions and the competition for natural resources, the major staple cereal crops, such as rice, are under production threat. On the other hand, the overuse of chemical fertilizers and pesticides to increase crop yield is deteriorating the growing environment for plants and animals, including humans. As such, sustainable management practices are the key method that can be employed to increase crop production without harming the environment. Plant growth-promoting bacteria (PGPB), such as the purple non-sulfur bacteria (PNSB), have recently gained much attention in crop production due to their ability to accumulate higher-value compounds that are highly beneficial to crops. Some of the major benefits PNSB holds are that it can fix atmospheric nitrogen, solubilize phosphate, remediate heavy metals, suppress methane emissions from waterlogged paddy fields, and assist in carbon sequestration. These benefits allow PNSB to be an important bacterium for improving plant growth and yield much more sustainably while benefiting the environment. This review article discusses the beneficial effects of PNSB on rice crop plants through careful screening of previous work in this area. The review also identifies the research gaps and suggests future research pathways to make PNSB an important bacteria for sustainable rice crop production. The review paper aims for the United Nation’s sustainable development goal number two, “Zero Hunger,” target 2.4, indicator 2.4.1, “Proportion of agricultural area under productive and sustainable agriculture”.

The Efficacy of 5-Aminolevulinic Acid-Producing Luteovulum sphaeroides Strains on Saline Soil Fertility, Nutrient Uptakes, and Yield of Rice

“…This is in accordance with the review by Maeda [49], where different PNSB can have one or two nitrogenases. Although the PNSB strains in the current study exhibited different characteristics, they can have synergetic effects [50]. Notably, the effect was shown in the total Na uptake in the treatment with the PNSB mixture at 0‰ salinity, which introduced the lowest amount of Na uptake compared with the other treatments (Table S4).…”

Utilization of Rhodopseudomonas palustris in Crop Rotation Practice Boosts Rice Productivity and Soil Nutrient Dynamics

“…Additionally, the application of PNSB has been previously documented to enhance N content in soil by fixing N 2 and making N available in ammonium (NH 4 + ) form [20,36,42,85]. Additionally, PNSB facilitates nitrogen use efficiency (NUE) in plants when combined with N fertilizer [22,23,40].…”

“…Additionally, the purple non-sulfur bacterium (PNSB) Rhodopseudomonas palustris (R. palustris) species has been observed to fix atmospheric nitrogen (N 2 ) while producing compounds aiding plant growth, such as 5-aminolevulinic acid (5-ALA) [19][20][21]. It has been demonstrated that the use of R. palustris can increase the growth and yield of a variety of crops, including pak choi [22][23][24], stevia [25], tobacco [26,27], mushroom [28], Chinese dwarf cherry [29], bean [30], and rice [19,[31][32][33][34][35].…”

Effects of LPS from Rhodobacter sphaeroides, a Purple Non-Sulfur Bacterium (PNSB), on the Gene Expression of Rice Root

“…Gram-negative bacteria are sometimes pathogenic, but to our knowledge, there has been no report of pathogenic PNSB and there have been no reports of opportunistic infection by PNSB in humans. PNSB have a wide variety of biotechnological applications in agriculture [ 3 , 4 , 5 ], aquaculture [ 6 , 7 ], biomaterial production [ 8 , 9 , 10 ], renewable energy production [ 11 , 12 ], wastewater treatment [ 13 ], and bioremediation [ 14 ].…”