Composite coatings of beeswax + naphthalene acetic acid preserved fruit quality and antioxidants in stored lemon fruits.

Lemon fruits are well recognized for their richness in antioxidants. The present study was conducted to maintain the antioxidant properties of lemon fruits under long term cold storage. Fruits were given different treatments of naphthalene acetic acid (NAA) @ 50, 100 and 150 ppm plus beeswax (BW) @ 2% and were stored at 6-8 °C and 90-95% RH for 60 days. At the end of storage, fruits coated with NAA (50 ppm) + BW (2%) retained 42.14 and 34.61% antioxidants, 62.72 and 56.54% phenolic content and 17.72 and 13.80% hydroxyl radical scavenging capacity in peel and pulp, respectively as compared to the control. This treatment also resulted in lesser weight loss (5.27%), higher ascorbic acid content (46.31 mg 100 ml-1 juice) and titratable acidity (5.23%). Hence, NAA + BW coatings were promising for the maintenance of the postharvest antioxidant quality of stored lemons. Supplementary Information: The online version contains supplementary material available at 10.1007/s10068-023-01364-4.

Methylglyoxal metabolism is altered during defence response in pigeonpea (Cajanus cajan (L.) Millsp.) against the spotted pod borer (Maruca vitrata).

Pigeonpea (Cajanus cajan ) production can be affected by the spotted pod borer (Maruca vitrata ). Here, we identified biochemical changes in plant parts of pigeonpea after M. vitrata infestation. Two pigeonpea genotypes (AL 1747, moderately resistant; and MN 1, susceptible) were compared for glyoxalase and non-glyoxalase enzyme systems responsible for methylglyoxal (MG) detoxification, γ-glutamylcysteine synthetase (γ-GCS), glutathione-S-transferase (GST) and glutathione content in leaves, flowers and pods under control and insect-infested conditions. MN 1 had major damage due to M. vitrata infestation compared to AL 1747. Lower accumulation of MG in AL 1747 was due to higher activities of enzymes of GSH-dependent (glyoxylase I, glyoxylase II), GSH-independent (glyoxalase III) pathway, and enzyme of non-glyoxalase pathway (methylglyoxal reductase, MGR), which convert MG to lactate. Decreased glyoxylase enzymes and MGR activities in MN 1 resulted in higher accumulation of MG. Higher lactate dehydrogenase (LDH) activity in AL 1747 indicates utilisation of MG detoxification pathway. Higher glutathione content in AL 1747 genotype might be responsible for efficient working of MG detoxification pathway under insect infestation. Higher activity of γ-GCS in AL 1747 maintains the glutathione pool, necessary for the functioning of glyoxylase pathway to carry out the detoxification of MG. Higher activities of GST and GPX in AL 1747 might be responsible for detoxification of toxic products that accumulates following insect infestation, and elevated activities of glyoxylase and non-glyoxylase enzyme systems in AL 1747 after infestation might be responsible for reducing reactive cabanoyl stress. Our investigation will help the future development of resistant cultivars.

Effect of herbicide stress on synchronization of carbon and nitrogen metabolism in lentil (Lens culinaris Medik.).

Weed invasion causes significant yield losses in lentil. Imazethapyr (IM), a broad-spectrum herbicide inhibits the biosynthesis of branched chain amino acids necessary for plant growth. Plant growth depends upon translocation of photo-assimilates and their partitioning regulated by carbon and nitrogen metabolism. This study aimed to investigate the impact of imazethapyr spray on carbon and nitrogen metabolism in tolerant (LL1397 and LL1612) and susceptible (FLIP2004-7L and PL07) lentil genotypes during vegetative and reproductive development. Significantly higher activities of invertases and sucrose synthase (cleavage) in leaves and in podwall and seeds during early phase of development in tolerant genotypes were observed as compared to susceptible genotypes under herbicide stress that might be responsible for providing hexoses required for their growth. Activities of sucrose synthesizing enzymes, sucrose phosphate synthase and sucrose synthase (synthesis) increased significantly in podwalls and seeds of LL1397 and LL1612 genotypes during later phase of development towards maturity while the activities decreased in FLIP2004-7L and PL07 genotypes under herbicide stress. Activities of nitrate and nitrite reductase, glutamine 2-oxoglutarate aminotransferase, glutamine synthetase and glutamate dehydrogenase were increased in leaves, podwalls and seeds of LL1397 and LL1612 under herbicide stress. A proper synchronization of carbon and nitrogen metabolism in tolerant lentil genotypes during vegetative and reproductive phase might be one of the mechanisms for their recovery from herbicide stress. This first ever comprehensive information will provide a basis for future studies on the molecular mechanism of source sink relationship in lentil under herbicide stress and will be utilized in breeding programmes.

Induced defense responses in cultivated and wild chickpea genotypes against Helicoverpa armigera infestation.

Five desi (GL 12,021, GL 29,095, GL 29,078, H11 22 and CSJ 515) and three wild (GLW 22, GLW 58 and GLW 187) chickpea cultivars showed induced defense response against Helicoverpa armigera infestation as a result of enhanced activities of superoxide dismutase, catalase, peroxidase, ascorbate peroxidase, glutathione reductase, polyphenol oxidase, phenylalanine ammonia lyase, tyrosine ammonia lyase in leaves, pod walls and seeds. Catalase activity increased in leaves of GL 12,021, H11 22, GL 29,095, CSJ 515, GLW 22, and GL 29,078 after infestation compared to resistant check; catalase and peroxidase activities in GL 29,095 and GL 29,078; ascorbate peroxidase and glutathione reductase activities in leaves of GLW 58. The increased activity of superoxide dismutase in pod wall of H1122; catalase in pod wall of 29,078, GL 29,095 and GL 22; ascorbate peroxidase and glutathione reductase in pod wall of GLW 58; phenylalanine ammonia lyase and tyrosine ammonia lyase in pod wall of GLW 187, H11 22, GL 20,978, GLW 22 and GLW 58 after infestation as compared to resistant check might be responsible for mitigating infestation induced oxidative stress. MDA content decreased in leaves, pod wall and seeds of GLW 187 and GL 12,021 after infestation. Lower percent pod damage (9.58-12.44%) in GL 12,021, GLW 187, GL 29,095, H11 22, GL 29,078, GLW 22 and GLW 58 as compared to resistant (16.18%) and susceptible (21.50) checks might be attributed to differential induced defense mechanism in them. The identified desi and wild genotypes might be used in breeding program to develop cultivars with improved resistance to herbivore.

Impact of post-emergent imazethapyr on morpho-physiological and biochemical responses in lentil (Lens culinaris Medik.).

Yield reduction in lentil crop due to weed infestation is a key hindrance to its growth due to poor weed-crop competition. Imazethapyr (IM), a selective herbicide, target acetolactate synthase (ALS) which catalyzes the first reaction in biosynthesis of branched chain amino acids, required for plant growth and development. The objective of the present study was to investigate the impact of IM treatment on weeds, ALS enzyme activity, antioxidant capacity, osmolyte accumulation, growth and yield related parameters in lentil genotypes. Two IM tolerant (LL1397 and LL1612) and two susceptible (FLIP2004-7L and PL07) lentil genotypes were cultivated under weed free, weedy check and IM treatments. Weed control efficiency reached its peak at 21 days after spray (DAS). Imazethapyr treatment decreased chlorophyll and carotenoid content up to 28 DAS with higher reduction in susceptible genotypes. FLIP2004-7L and PL07 had reduced plant height and lower number of pods under IM treatment which resulted in decreased seed yield. Higher ALS activity in LL1397 and LL1612 at 21 DAS, higher antioxidant capacity and glycine betaine content both at 21 and 28 DAS and lower decrease in relative leaf water content might be mediating herbicide tolerance in these genotypes that led to higher seed yield. The identified IM tolerance mechanism can be used to impart herbicide resistance in lentil. Supplementary Information: The online version contains supplementary material available at 10.1007/s12298-022-01244-x.

Juvenile heat stress tolerance in Triticum durum-Aegilops tauschii derived synthetics: a way forward for wheat improvement.

BACKGROUND: Exponentially increasing population and everchanging climatic conditions are two major concerns for global food security. Early sowing in the second fortnight of October is an emerging trend with farmers in Indo Gangetic Plains to avoid yield losses from terminal heat stress. This also benefits the use of residual soil moisture of rice crop, conserving about one irrigation. But most of the available wheat cultivars are not well adapted to early-season sowing. METHODS AND RESULTS: Two in-house developed SHWs, syn14128 and syn14170, were screened for juvenile heat stress. Seedling length, biochemical parameters, and expression of amylase gene immediately after heat shock (HS) of 45 °C for 12 h and 20 h, and 24 h indicated significantly lower malondialdehyde, hydrogen peroxide, and higher free radical scavenging activities. Syn14170 reported higher total soluble sugar (TSS) under both HS periods, while syn14128 had a sustainable TSS content and amylase activity under HS as well as the recovery period. CONCLUSIONS: Both the SHWs had lower oxidative damage along with high free radical scavenging under heat stress. The higher expression of amy4 along with sustainable TSS after heat stress in syn14128 indicated it as a potential source of juvenile heat stress tolerance. Variable response of SHWs to different biochemical parameters under heat stress opens future perspectives to explore the enzymatic pathways underlying these responses.

Marker-assisted introgression of genes into rye translocation leads to the improvement in bread making quality of wheat (Triticum aestivum L.).

Introgression of genes from related species can be a powerful way to genetically improve crop yields, but selection for one trait can come at the cost to others. Wheat varieties with translocation of the short arm of chromosome 1 from the B genome of wheat (1BS) with the short arm of chromosome 1 from rye (1RS) are popular globally for their positive effect on yield and stress resistance. Unfortunately, this translocation (1BL.1RS) is also associated with poor bread making quality, mainly due to the presence of Sec-1 on its proximal end, encoding secalin proteins, and the absence of Glu-B3/Gli-B1-linked loci on its distal end, encoding low molecular weight glutenin subunits (LMW-GS). The present study aims to replace these two important loci on the 1RS arm with the wheat 1BS loci, in two popular Indian wheat varieties, PBW550 and DBW17, to improve their bread-making quality. Two donor lines in the cultivar Pavon background with absence of the Sec-1 locus and presence of the Glu-B3/Gli-B1 locus, respectively, were crossed and backcrossed with these two selected wheat varieties. In the advancing generations, marker assisted foreground selection was done for Sec-1- and Glu-B3/Gli-B1+ loci while recurrent parent recovery was done with the help of SSR markers. BC2F5 and BC2F6 near isosgenic lines (NILs) with absence of Sec-1 and presence of Glu-B3/Gli-B1 loci were evaluated for two years in replicated yield trials. As a result of this selection, thirty promising lines were generated that demonstrated improved bread making quality but also balanced with improved yield-related traits compared to the parental strains. The study demonstrates the benefits of using marker-assisted selection to replace a few loci with negative effects within larger alien translocations for crop improvement.

Methylglyoxal detoxification pathway - Explored first time for imazethapyr tolerance in lentil (Lens culinaris L.).

Lentil is an important pulses crop but it's short stature and slow growth rate make it vulnerable to weed competition, limiting crop productivity. There is need to identify herbicide tolerant genotypes and their tolerance mechanism. The present investigation was conducted to understand the effect of imazethapyr (IM) treatment on accumulation of methylglyoxal (MG) and its detoxification mechanism in IM-tolerant (LL1397 and LL1612) susceptible (FLIP2004-7L and PL07) genotypes sown under control (weed free), weedy check (weeds were growing with crop) and sprayed with imazethapyr. The enzymes of glyoxalase pathway (glyoxalase I, II and III) and non glyoxalase pathway (methylglyoxal reductase), lactate dehydrogenase (LDH), glutathione content, gamma-glutamyl-cysteine synthetase (γ-GCS) were estimated in lentil genotypes at different days after spray. Higher activities of glyoxalase I, II and III and MGR along with the increased glutathione content (GSH) content in LL1397 and LL1612 under IM treatment as compared to FLIP2004-7L and PL07 might be responsible for lowering MG accumulation and increasing lactate content, which is end product of these pathways. Enhanced LDH activity in LL1397 and LL1612 might be responsible for energy production via TCA cycle that might be responsible for growth and recovery of tolerant genotypes after IM treatment. Higher γ-GCS activity in tolerant genotypes led to increased glutathione content required for glyoxalase pathway. However, decreased activities of glyoxalase enzymes and MGR in susceptible genotypes result in MG accumulation which limit plant growth. This is the first ever study elucidating the role of MG detoxification pathway conferring IM tolerance in lentil.

Insights into carbon and nitrogen metabolism and antioxidant potential during vegetative phase in quinoa (Chenopodium quinoa Willd.).

The present investigation was carried out to understand the impact of carbon and nitrogen metabolism in quinoa genotypes IC411824, IC411825, EC507747 and EC507742 during pre-anthesis stage. It was observed that activities of acid invertase, sucrose synthase (cleavage) and sucrose phosphate synthase (SPS) increased up to 75 days after sowing (DAS) and this might be responsible for providing reducing sugars for the development of vegetative parts. Enhanced activities of nitrate reductase, glutamate synthase, glutamine synthetase during vegetative growth of leaves and stem at 90 DAS assist the fixation of ammonia on glutamate molecule to synthesize amino acids at early stages. However, the glutamate dehydrogenase and nitrite reductase play a central role in the re-assimilation of amides from the amino group of asparaginase. As a result, these photosynthetic products will be responsible for providing both the energy and the C-skeletons for ammonium assimilation during amino acid biosynthesis. Leaves and stem of IC411824 and IC411825 had higher total phenol and total flavonoid content. DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity was found to be higher in leaves of IC411825 and in stem of IC411824 and IC411825 indicating their capability to act as natural antioxidants.

Impact of phosphorous-deficit conditions on morpho-physiological traits and phosphorous metabolism in chickpea genotypes.

Chickpea, an important food legume, is primarily grown on marginal soils with low soil fertility. Although chickpea can fix N, soil phosphorus (P) deficiency in crop growing areas is a major limiting factor for chickpea production. This study was undertaken to evaluate twenty-five chickpea cultivars for morpho-physiological traits and yield under low and normal phosphorous conditions. Based on morpho-physiological traits such as length and area of roots and shoots, root length density, root and shoot biomass, chlorophyll content, number of nodules and root tips, tolerance indices and yield, these cultivars were characterised into susceptible (ICC67, ICC1915, ICC2593, ICC5337, ICC5879, ICC8950, ICC13441, ICC1483, ICC15606 and ICC15888), tolerant (ICC10755, IG72070, ICCV97105, ICCV2, ICCV92809, ICCV92337 and ICCV95423) and the remaining cultivars were moderately tolerant to phosphorous-deficit conditions. Higher activities of enzymes of phosphorous metabolism such as acid phosphatase and phytase in roots and nodules of tolerant chickpea cultivars (ICCV97105, ICCV92337, ICCV95423) as compared to susceptible cultivars (ICC67, ICC15606, ICC15888) at different developmental stages might be attributing to their better performance for growth parameters and productivity traits under phosphorous-deficit conditions.

Desi and kabuli chickpea cultivars had differential behaviour towards salinity stress tolerance.

Twenty chickpea cultivars were germinated under control and different levels of salt stress induced by sodium chloride and out of these, three desi (PDG 3, GL 12003, C 106) and two kabuli (FLIP-08-125-C and GLK 28127) cultivars were selected on the basis of embryonic axis growth, biomass, salinity stress tolerance index. Antioxidative enzymes, non-enzymatic antioxidants proline and proline metabolizing enzymes and free radical scavenging activities were estimated in embryonic axes of these selected cultivars under control and salt stressed conditions. Higher activities of catalase and Δ1-pyrroline-carboxylate synthetase (P5CS) and sustained activities of superoxide dismutase (SOD) and ascorbate peroxidase (APX) in embryonic axis along with higher SOD and glutathione reductase and maintained APX in cotyledons might be mediating salt stress tolerance in kabuli cultivar FLIP-08-125-C. Higher proline content, enhanced P5CS activity and decreased proline dehydrogenase activity in embryonic axis along with higher free radical scavenging activities both in cotyledons and embryonic axis in desi cultivar PDG 3 might be mediating salt stress tolerance by maintaining osmotic balance and reducing oxidative damage.

Comparison of cultivated and wild chickpea genotypes for nutritional quality and antioxidant potential.

Fifteen cultivated (Ten desi, five kabuli) and fifteen wild species of chickpea (Cicer arietinum L.) were compared for nutritional traits, antinutritional factors and antioxidant potential. The average crude protein content in desi, kabuli and wild species was found to be 25.31%, 24.67% and 24.30%, respectively; total soluble sugars in these genotypes were 38.08, 43.75 and 33.20 mg/g, respectively and total starch content in these genotypes was 34.43, 33.43 and 28.77%. Wild species had higher antioxidant potential as compared to cultivated genotypes due to higher free radical scavenging activity, ferric reducing antioxidant power and reducing power. Kabuli genotypes had lower antioxidant potential than desi genotypes. Desi genotype, GL 12021 had high crude protein and total starch content, lower phytic acid and saponin content and higher antioxidant potential. GNG 2171 had high crude protein and total soluble sugar content and lower tannin and phytic acid content. Kabuli genotype L 552 possessed high total soluble sugar and total starch content, high Zn and Fe content and lower tannin, saponin and trypsin inhibitor content. Wild species C. pin ILWC 261 had high crude protein, lower phytic acid and trypsin inhibitor content and higher DPPH radical scavenging activity and hydroxyl radical scavenging activity. The observed diversity for quality traits in cultivated and wild genotypes can be further used.

Evaluation of nutritional quality and antioxidant potential of pigeonpea genotypes.

Three released cultivars, forty four advance breeding lines and three wild species of pigeonpea (Cajanus cajan L. Millsp) were evaluated for nutritional, antinutritional traits and antioxidant potential so as to identify promising genotypes. The average content of total soluble sugars, starch and total soluble proteins was found to be 43.66, 360.51 and 204.54 mg/g, respectively. Antioxidant potential in terms of free radical scavenging activity (DPPH), ferric reducing antioxidant power (FRAP), reducing power, hydroxyl radical scavenging activity and superoxide anion radical scavenging activity was estimated. The diversity was observed in genotypes with all the traits. AL 1960, AL 2000, AL 2009 and AL 2046 had high total soluble proteins, medium antinutritional factors and good antioxidant potential. AL 201, AL 1931, AL 1932, AL 1960, AL 2046, AL 2049 and AL 2060 had good nutritional value as protein and starch content ranged from 20 to 23 and 42 to 52%, respectively. Wild species C. scarabaeoides 1CP15683/W15 had lower carbohydrates, proteins, and antinutritional traits while high antioxidant potential due to high total phenols, DPPH, FRAP and reducing power. The diversity observed in genotypes with all the traits could be further used to develop nutritionally important genotypes.