Wheat endophytes and their potential role in managing abiotic stress under changing climate

Abstract

Wheat (Triticum aestivum L.) cultivation differs considerably in respect of soil type, temperature, pH, organic matter, moisture regime, etc. Among these, rising atmospheric temperature due to global warming is most important as it affects grain yield drastically. Studies have shown that for every 1°C rise in temperature above wheat's optimal growing temperature range of 20-25°C, there is a decrease in 2.8 days and 1.5 mg in the grain filling period and kernel weight, respectively, resulting in wheat yield reduction by 4-6 quintal per hectare. Growing demand for food and multidimensional issues of global warming may further push wheat crop to heat stress environments that can substantially affect heading duration, percent grain setting, maturity duration, grain growth rate and ultimately total grain yield. Considerable genetic variation exists in wheat gene pool with respect to various attributes associated with high temperature and stress tolerance; however, only about 15% of the genetic variability could be incorporated into cultivated wheat so far. Thus, alternative strategies have to be explored and implemented for sustainable, more productive and environment friendly agriculture. One of the feasible and environment friendly option is to look at micro-organisms that reside inside the plant without adversely affecting its growth, known as 'endophytes', and these colonize virtually all plant organs such as roots, stems, leaves, flowers and grains. The relationship between plant and endophytes is vital to the plant health, productivity and overall survival under abiotic stress conditions. Thus, it becomes imperative to enlist the endophytes (bacterial and fungal) isolated till date from wheat cultivars, their mechanism of ingression and establishment inside plant organs, genes involved in ingression, the survival advantages they confer to the plant under abiotic stress conditions and the potential benefits of their use in sustainable wheat cultivation.

Screening and Characterization of Potential Plant Growth-Promoting Endophytes of Wheat (Triticum aestivum)

“…PGPR traits; antagonistic bacteria; Tritium aestivum; 16s rRNA 2 Wheat (Triticum aestivum) is grown in 17% of farmland globally and provides about 82% of the protein source and 80% of the calories for the global population [2][3][4]. It is grown annually on around 220 million hectares area and approximately 775 metric tons of yield is reported in the world per year [5]. While in India it is grown on around 30 million hectares with 104 metric tons of yield per year, and India is the second leading producer of wheat in the world.…”

Rapid growth of antimicrobial resistance: the role of agriculture in the problem and the solutions

“…Whole grains carry a range of probiotic lactic acid bacteria (Carrizo et al 2016 ; Wu et al 2018 ) with a range of Lactobacillus Pediococcus , Leuconostoc and Enterococcus species capable of performing sourdough fermentation. Bacterial and fungal endophytes are known as plant probiotics and are extensively documented in grains (Ahlawat et al 2021 ; Makar et al 2021 ) and legumes (Ruiz Mostacero et al 2021 ). Recently microbiota of poultry feed raw ingredients such as meat and bone meal, wheat, corn, canola, barley, soybean, millrun, sorghum, poultry oil, oats, limestone and bloodmeal was described using the 16S methodology (Haberecht et al 2020 ).…”

Feed Safety and the Development of Poultry Intestinal Microbiota

“…Endophytes are endosymbionts, most likely bacteria or fungi, that live inside or on the plant in a mutually beneficial relationship and therefore are a big part of the plant and seed residential microbiota. Bacterial and fungal endophytes are well-reviewed and documented in grains [ 63 , 64 , 65 ] and in legumes [ 66 ], thus adding more evidence to the observation of grain microbiota. The high prevalence of probiotics in grains and above discussed high prevalence of pathogens in protein-rich feedstuffs indicate that the first feed offered to hatchlings, selected and formulated to promote the growth of probiotics and inhibit pathogens, should be grain-based and rely on grains and cereals as a protein source for the first few days of gut microbiota establishment.…”