Adaptation strategies of forage soybeans cultivated on acidic soils under cool climate to produce high quality forage

Lipid mediated plant immunity in susceptible and tolerant soybean cultivars in response to Phytophthora sojae colonization and infection

BACKGROUND

Soybean is one of the most cultivated crops globally and a staple food for much of the world's population. The annual global crop losses due to infection by Phytophthora sojae is currently estimated at $20B USD, yet we have limited understanding of the role of lipid mediators in the adaptative strategies used by the host plant to limit infection. Since root is the initial site of this infection, we examined the infection process in soybean root infected with Phytophthora sojae using scanning electron microscopy to observe the changes in root morphology and a multi-modal lipidomics approach to investigate how soybean cultivars remodel their lipid mediators to successfully limit infection by Phytophthora sojae.

RESULTS

The results reveal the presence of elevated biogenic crystals and more severe damaged cells in the root morphology of the infected susceptible cultivar compared to the infected tolerant cultivars. Furthermore, induced accumulation of stigmasterol was observed in the susceptible cultivar whereas, induced accumulation of phospholipids and glycerolipids occurred in tolerant cultivar.

CONCLUSION

The altered lipidome reported in this study suggest diacylglycerol and phosphatidic acid mediated lipid signalling impacting phytosterol anabolism appears to be a strategy used by tolerant soybean cultivars to successfully limit infection and colonization by Phytophthora sojae.

Potential of developing podzolic soil-based potting media from wood ash, paper sludge and biochar

BACKGROUND AND OBJECTIVES

Organic waste management in environmentally sustainable way is important not only to reduce the negative impacts on ecosystems but also valorizing the waste resources. Herein we evaluated the potential of wood ash (WA) and paper sludge (PS) wastes from a pulp and paper mill as potting media and their effects on the physicochemical properties of podzolic soil.

METHODS

WA, PS and biochar (BC) was mixed in different combinations with a sandy loam podzolic soil. Potting media treatments included: T1-soil (negative control); T2-Promix^TM (positive control); T3-50%soil+50%WA; T4-75%soil+25%WA; T5-50%soil+50%PS; T6-75%soil+25%PS; T7-75%soil+25%BC; T8-25%soil+50%WA+25%BC; T9-50%soil+25%WA+25%BC; T10-25%soil+50%PS+25%BC; T11-50%soil+25%PS+25%BC, T12- 25%soil+25%WA+25%PS+25%BC and replicated three times.

RESULTS

Potting media treatments expressed significant (p < 0.00) effects on pH, bulk density, total porosity, field capacity, plant available water (PAW) and water retention curves. Potting media amended with WA showed high pH range (8-12) while PS amendments exhibited pH in range where most plant nutrients are available (6.5-7.5). Results depicted significantly lower bulk density, and increased total porosity and water holding capacity of potting media amended with WA and PS. BC addition further enhanced the water retention properties compared to combinations without BC. T6, T10 and T11 produced higher amounts of PAW with desired pH compared to T1 and T2.

CONCLUSION

WA, PS and BC showed high potential for developing podzolic soil-based potting media, but their effects on plant growth and elemental uptake need to be investigated.

Assessing the Effects of Agronomic Management Practices on Soybean (Glycine max L.) Post-Grain Harvest Residue Quality in the Lower Mississippi Delta

Livestock producers often resort to either baling or grazing of crop residues due to high hay prices and reduced supply of other forages and silage in the markets. Soil-water-crop management practices can affect residue nutrient qualities for its use as cattle feedstock. A two-year study (2018–2019) was conducted to investigate the effects of irrigation (AI, all row-irrigation; ARI, alternate row irrigation; and RF, rainfed) and planting pattern, PP (SR, single row; and TR, twin-row) on soybean (maturity group IV cv. 31RY45 Dyna-Gro) post-grain harvest residue quality such as crude protein (CP), acid detergent fiber (ADF), neutral detergent fiber (NDF), acid detergent lignin (ADL), net energy for maintenance (NEM), net energy for gain (NEG), net energy for lactation (NEL), total digestible nutrients (TDN), and relative feed value (RFV). Irrigation has a significant effect on CP, ADF, NDF, and TDN while PP affected only NDF. All the above parameters were significantly affected except NEM by the contrasting climate conditions, particularly during July through August coinciding with early crop reproductive stages and maturity. The RFV values ranged from 70.4 to 81.6 and this lower range was attributable to nutrient translocation to seeds and higher lignification during plant senescence towards the grain filling stage of the crop as good quality hay records over 120 RFV. These results indicate that both irrigation and weather during soybean seed development can alter post-grain harvest residue quality parameters, thereby playing critical roles in its RFV.

Root membrane lipids as potential biomarkers to discriminate silage-corn genotypes cultivated on podzolic soils in boreal climate

Root membrane lipids are important biomolecules determining plant's ability to adapt to different growing environmental or climatic conditions. Herein, we demonstrate the potential use of root membrane lipids as biomarkers to discriminate silage-corn genotypes based on herbicide and insect/pest resistance genetic traits when cultivated on podzolic soils under short growing and moderately warm summer season in boreal climate. Lipids in root membranes of field grown silage-corn genotypes were previously quantified at crop maturity by ultra-high-performance liquid chromatography-hydrophilic interaction chromatography-heated electrospray ionization mass spectrometry. The lipid identified and quantified in silage-corn roots were phospholipids, glycolipids and sphingolipids. Following hierarchical cluster analysis, three groups of membrane lipids were observed to be very effective in segregating the five silage-corn genotypes. The first group consisted of hexosylceramide (HexCer), phosphatidylcholine (PC) and phosphatidylinositol (PI). The second group consisted of lysophosphatidic acid (LPA16:0) and lysophosphatidylcholine (LPC16:0), while the third group consisted of 37 molecular species from observed lipids (phospholipids, glycolipids, sphingolipids). Partial least squares-discriminant analysis (PLS-DA) based on 37 membrane lipid species, as well as principal component analysis using the variables important in projection derived from the PLS-DA segregated the five silage-corn genotypes into three groups according to their pesticide/herbicide resistant traits. This study is second to none using root lipidomics in discriminating different silage-corn genotypes based on their herbicide and insect/pest resistance genetic traits for cultivation in boreal climates. The segregated genotypes possess three different genetic traits for herbicide and insect/pest resistance including VT Double Pro (VT2P), VT Triple Pro Roundup Ready (VT3P/RR) and Roundup Ready-2 corn (RR2). These findings demonstrate that root membrane lipids could serve as appropriate chemical biosignatures to identify silage-corn genotypes based on herbicide and insect/pest resistance genetic traits suitable for cultivation in boreal climates.

The soybean root membrane lipids and forage quality data in response to field cultivation on agricultural podzols in boreal climates

The objective of this data in brief article is to represent the associated data set regarding our published paper in Plant Science Nadeem et al., 2019. Data set represent soil acid phosphatase activity, association of individual molecular species of four major lipid classes with soybean forage quality indices when cultivated in boreal podzolic soils under cool climatic conditions. Phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidic acid (PA) and acylated glucosyl betasitosterol ester (AGIcSiE) molecular species grouped the soybean forage quality indices in different quadrants on principal component analyses. Furthermore, the total lipid profile and correlation of major lipid species with forage quality indices are included in this data in brief article. This data set support the main findings described in Nadeem et al., 2019.