Bioprocessing of common pulses changed seed microstructures, and improved dipeptidyl peptidase-IV and α-glucosidase inhibitory activities.

Type 2 diabetes mellitus (T2DM) is a leading cause of death globally. T2DM patients experience glucose intolerance, and inhibitors of dipeptidyl peptidase IV (DPP-IV) and α-glucosidase are used as drugs for T2DM management. DPP-IV and α-glucosidase inhibitors are also naturally contained in foods, but their potency can be affected by the food matrix and processing methods. In this study, germination and solid-state fermentation (SSF) were used to alter pulse seed microstructures, to convert compounds into more bioactive forms, and to improve their bioaccessibility. Germination substantially modified the seed microstructure, protein digestibility, contents and profiles of phenolic compounds in all the pulses. It also increased DPP-IV and α-glucosidase inhibitory activities in chickpeas, faba beans and yellow peas. Compared to germination, SSF with Lactobacillus plantarum changed the content and the profile of phenolic compounds mainly in yellow peas and green lentils because of greater disruption of the seed cell wall. In the same pulses, heat treatment and SSF of flour increased DPP-IV and α-glucosidase inhibitory activities. The results of this study suggest that germination and SSF with L. plantarum are effective and simple methods for modulating phenolic and protein profiles of common pulses and improve the action on DPP-IV and α-glucosidase.

Evaluation of cultivated and wild genotypes of Lens species under alkalinity stress and their molecular collocation using microsatellite markers.

In this study, 285 lentil genotypes were phenotyped under hydroponic and alkaline field conditions. Significant genotypic variation for alkalinity stress was observed among the six Lens species screened hydroponically and in the field having pH up to 9.1. The crucial parameters, like whole Na+ and K+ contents and the Na+/K+ ratio at 40 mM NaHCO3 were found significantly correlated with seedling survivability under hydroponics (r = -0.95, r = 0.93 and -0.97). Genotypes, ranked on the bases of seed yield, restricted uptake of Na+ with thick pith area, increased vascular bundles, less H2O2 production and low Na+/K+ ratio, were found important physio-anatomical traits for alkalinity stress tolerance. The proper regulation of Na+ uptake was found for maintaining higher K+. This relationship is probably the main factor responsible for a better mechanism for tolerance to high pH up to 9.1 in tolerant breeding lines PDL-1 and PSL-9 (cultivars) and ILWL-15, ILWL-192 and ILWL-20 (wild accessions). Based on UPGMA dendrogram, all the genotypes were clustered into four diverse groups. DMRT was implied within the group to differentiate genotypes based on phenotypic response under alkalinity stress. These results can be utilized for selecting diverse parents for developing alkalinity tolerant genotypes.

Photomorphogenesis and pigment induction in lentil seedling roots exposed to low light conditions.

Although roots are normally hidden in soil, they may inadvertently be exposed to low light levels in experiments or in natural conditions through cracks or light transmittance through the soil. Light has been implicated in root morphogenesis. Thus, effects of low light conditions on lentil (Lens culinaris L. cv. Verte du Puy) root morphology and root pigmentation were studied. Lentil seedlings were grown in peat or transparent, nutrient-fortified agar at a 12-h light (PAR 240 µmol · m(-2) · s(-1)), 12-h dark cycle. Roots were exposed to low levels (≈ 1-10 µmol · m(-2) · s(-1)) of broadband white light, either directly or indirectly by aboveground light penetrating the growth medium. Control roots were grown in darkness. In situ spectroscopy was used to measure transmittance and reflectance spectra of intact root tissue by mounting the upper part of the primary root directly in a spectrophotometer equipped with an integrating sphere attachment. The transmittance and reflectance spectra were used to calculate the in situ root absorbance spectrum. Absorbance bands were found in the regions 480-500 nm and 650-680 nm, possibly due to low levels of root-localised carotenoids and chlorophylls, respectively. Low light levels (≈ 1-10 µmol · m(-2) · s(-1) ) transmitted through the growth medium significantly increased root pigment concentration and root biomass, and altered root morphology by enhancing lateral root formation and inhibiting root elongation relative to roots grown in complete darkness. The light-induced changes in root morphogenesis and pigmentation appear to be primarily due to upper root light perception.

Moisture dependent physical and mechanical properties of green laird lentil (Lens culinaris) grains.

This study was conducted to investigate some moisture dependent physical and mechanical properties of green laird lentil grains namely, grain dimensions, thousand grain mass, surface area, projected area, sphericity, bulk density, true density, porosity, terminal velocity, static coefficient of friction against different materials. The average diameter and thickness were 6.72 and 2.58 mm, at a moisture content of 11.36% d.b., respectively. In the above moisture range, the arithmetic and geometric mean diameters increased from 5.340 to 5.685 mm and from 4.879 to 5.260 mm, respectively, while the sphericity decreased from 0.727 to 0.744. In the moisture range from 11.36-25.08% d.b., studies on rewetted green laird lentil grains showed that the thousand grain mass increased from 72.00 to 73.90 g, the projected area from 36.98 to 55.60 mm2, the true density from 1170 to 1420 kg m(-3), the porosity from 29.91 to 55.63% and the terminal velocity from 5.90 to 7.10 m s(-1). The bulk density decreased from 820 to 630 kg m(-3) with an increase in the moisture content range of 11.36-25.08% d.b. The static coefficient of friction of green laird lentil grains increased against surfaces of six structural materials, namely, rubber (0.51-0.58), aluminum (0.48-0.57), stainless steel (0.38-0.44), galvanized iron (0.42-0.50), glass (0.35-0.40) and MDF (medium density fiberboard) (0.31-0.36) as the moisture content increased from 11.36-25.08% d.b.

Zinc is critically required for pollen function and fertilisation in lentil.

The role of zinc (Zn) in reproduction of lentil (Lens culinaris Medik. cv. DPL 15) and the extent to which the Zn requirement for reproduction can be met through supplementation of Zn at the time of initiation of the reproductive phase have been investigated. Low supply (0.1micromol/L) of Zn reduced the size of anthers, the pollen producing capacity and the size and viability of the pollen grains. Scanning electron microscopy (SEM) of pollen grains of Zn deficient plants showed enhanced thickening of exine and wide and raised muri. In vitro germination of pollen grains was reduced by >50% and growth of pollen tubes was retarded. Unlike Zn sufficient plants, the cuticle around the stigmatic papillae of Zn deficient plants remained intact, preventing the interaction between pollen grains and stigmatic exudates that provides the polarity for the growth of pollen tubes through the stylar tract. Zn deficiency increased the activity of acid phosphatase and peroxidase in extracts of pollen grains. Histochemical localisation on the stigmatic surface and native PAGE of the enzyme extracts of pollen grain and stigma exudates showed enhanced expression of acid phosphatase and peroxidase and suppressed expression of esterase in response to Zn deficiency. Zn deficiency reduced the setting of seeds and also their viability. The effect on seed setting was more marked than on in vitro germination of pollen grains, suggesting that the latter was not the exclusive cause of inhibition of fertility. Possibly, loss of fertility was also caused by impairment in pollen-pistil interaction conducive to pollen tube growth and fertilisation. Impairment in pollen structure and function and seed setting was observed even when plants were deprived of Zn at the time of flowering, but to a lesser extent than in plants maintained with low Zn supply from the beginning. Increasing the Zn supply from deficient to sufficient at the initiation of flowering decreased the severity of Zn deficiency effects on pollen and stigma morphology, pollen fertility and seed yield. In conclusion, structural and functional changes induced in pollen grains and stigma of Zn deficient plants and associated decrease in seed setting of lentil indicate a critical requirement of Zn for pollen function and fertilisation that can be partially met by supplementing Zn at the onset of the reproductive phase.

Comparative study of the conformational lock, dissociative thermal inactivation and stability of euphorbia latex and lentil seedling amine oxidases.

The thermal stability of copper/quinone containing amine oxidases from Euphorbia characias latex (ELAO) and lentil seedlings (LSAO) was measured in 100 mM potassium phosphate buffer (pH 7.0) following changes in absorbance at 292 nm. ELAO was shown to be about 10 degrees C more stable than LSAO. The dissociative thermal inactivation of ELAO was studied using putrescine as substrate at different temperatures in the range 47-70 degrees C, and a "conformational lock" was developed using the theory pertaining to oligomeric enzyme. Moreover ELAO was shown to be more stable towards denaturants than LSAO, as confirmed by dodecyl trimethylammonium bromide denaturation curves. A comparison of the numbers of contact sites in inter-subunits of ELAO relative to LSAO led us to conclude that the higher stability of ELAO to temperature and towards denaturants was due to the presence of larger number of contact sites in the conformational lock of the enzyme. This study also gives a putative common mechanism for thermal inactivation of amine oxidases and explains the importance of C-terminal conserved amino acids residues in this class of enzymes.