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Corn cobs consist primarily of a lignocellulosic material comprising hemicellulose, cellulose, and lignin in a crystalline state, which is resistant to microbial saccharification. Bioethanol production from corn cobs has rarely been attempted, especially using chemical pretreatment methods. The present study deals with the production and purification of fungal (Phanerochaete chrysosporium MTCC 787 and Pleurotus florida PAU 22‐01) extracellular ligninolytic enzymes – lignin peroxidase (LiP), manganese peroxidase (MnP), and laccase (Lac) – followed by their utilization for the biological pretreatment of corn cobs along with saccharification using commercial cellulase. Crude LiP, MnP, and Lac demonstrated specific activity of 2.23, 2.1, and 2.63 U/mg, respectively. The one‐step purification of crude enzyme using diethyl amino ethyl (DEAE) cellulose ion exchange chromatography resulted in 11.3, 10.1 and 8.62‐fold purification of LiP, MnP and Lac activity, respectively, with corresponding specific activity of 25.1 U/mg (LiP), 21.2 U/mg (MnP) and 22.7 U/mg (Lac) in the partially purified ligninozymes. Using the latter, biological pretreatment of 2.5 g corn cobs in a reaction volume of 30 mL containing approximately 200 units of Lac, Lip and MnP enzymes (in phosphate buffer, pH 6) resulted in a maximum of 78.4% delignification with a saccharification efficiency of 97.1% using commercial cellulases. [ABSTRACT FROM AUTHOR]

Background and Objectives: Maize is a major ingredient of animal feed. However, its nutritional quality is poor due to the deficiency of essential amino acid methionine. The animal feed, prepared as a corn–legume mixture to balance the nutritional quality, remains deficient in methionine. Therefore, the bio‐fortification of maize for methionine is the best option to make nutritionally balanced animal and poultry feed. The present study was designed to evaluate the profile of zeins and the expression profile of methionine‐associated target genes in high‐ and low‐methionine maize. Findings: Results of sodium dodecyl sulfate‐polyacrylamide gel electrophoresis revealed that the 10‐kDa zein was accumulated during kernel development, and its accumulation was higher in high methionine lines. Gene expression analysis through real‐time polymerase chain reaction revealed that higher expression of 10‐ and 18‐kDa zeins is associated with higher methionine accumulation. Conclusions: The above results indicate that 10‐ and 18‐kDa genes are the potential targets for the methionine bio‐fortification in maize, which is required for animal and poultry feed. Significance and Novelty: The present study suggests that 10‐ and 18‐kDa genes are the major source of methionine, and the regulation of these genes is crucial to enhancing the methionine content in maize. The results indicate that these genes are potential targets for genetic engineering in maize to enhance methionine accumulation. [ABSTRACT FROM AUTHOR]

Background and Objectives: Zein proteins of maize endosperm are nutritionally poor, but important for vitreous kernel texture. The Opaque‐2 mutation enhances the protein quality but downregulates zein expression, distorting the kernel texture. Quality protein maize (QPM) is nutritionally improved, hard endosperm maize developed by introgression of endosperm modifiers under an opaque‐2 background. The present study aims to analyze the variability in zein expression patterns in normal, opaque‐2, and QPM lines through sodium dodecyl sulfate‐polyacrylamide gel electrophoresis and two‐dimensional gel electrophoresis analyses. Findings: Results revealed that the total number of zein isoforms is almost similar in opaque‐2, normal, and QPM lines. Overall, in this study, it is concluded that the opaque‐2 mutation specifically affects the expression of high‐molecular‐weight zeins, which are being counterbalanced by the expression of low‐molecular‐weight zein isoforms and nonzein proteins. Conclusion: Genomic data retrieval studies revealed the possible presence of multiple 27 kDa isoforms with varied isoelectric points (pI), which is a subject for further investigation. The differential expression of 15 kDa zein in QPM emerged as a novel player in endosperm modification. Significance and Novelty: The present study provides insight into the diversified expression of zeins in different maize types. The variable isoform expression has the potential to generate stable QPM lines by targeting effective isoforms, ensuring endosperm modification without hampering the nutritional quality. [ABSTRACT FROM AUTHOR]

Context: Phytic acid is the major storage form of phosphorus in cereals and is considered an anti-nutritional factor because it chelates major mineral micronutrient cations, resulting in micronutrient malnutrition in humans. For monogastric animals fed maize (Zea mays L.) grains, the stored phosphorus does not release into the digestive tract, leading to phosphorus deficiency and environmental pollution. Aims: The aim of the study was to develop maize lines with a lower level of phytic acid that might substantially enhance the nutritional value of maize. Methods: The lpa1 mutant allele conferring low phytic acid was transferred into the parental lines of popular maize hybrid DMH 121 (i.e. BML 6 and BML 45) through marker-assisted backcross breeding. Foreground selection was performed using a co-dominant single nucleotide polymorphism marker through a high-resolution melting approach, and background selection was undertaken using 50–55 polymorphic sequence-tagged microsatellite site markers. Key results: Near-isogeneic lines were produced with >90% recurrent parental genome and reduction of phytic acid content by up to 44–56% compared with the original lines. Conclusions: The near-isogeneic lines carrying lpa1 can be used to reconstitute DHM 121 with low phytate content. Implications: The low-phytate maize hybrids produced can be useful in reducing micronutrient malnutrition in humans, as well as environmental pollution. Phytic acid is an anti-nutritional factor that chelates major mineral micronutrient cations, resulting in micronutrient malnutrition in humans. In this study, the lpa1 mutant allele was transferred into the parental lines of DMH 121 (i.e BML 6, and BML 45) through marker-assisted backcross breeding. Near-isogeneic lines were produced with 44–56% reduction of phytic acid content relative to the original lines. [ABSTRACT FROM AUTHOR]

The development of resistant maize cultivars is the most effective and sustainable approach to combat fungal diseases. Over the last three decades, many quantitative trait loci (QTL) mapping studies reported numerous QTL for fungal disease resistance (FDR) in maize. However, different genetic backgrounds of germplasm and differing QTL analysis algorithms limit the use of identified QTL for comparative studies. The meta-QTL (MQTL) analysis is the meta-analysis of multiple QTL experiments, which entails broader allelic coverage and helps in the combined analysis of diverse QTL mapping studies revealing common genomic regions for target traits. In the present study, 128 (33.59%) out of 381 reported QTL (from 82 studies) for FDR could be projected on the maize genome through MQTL analysis. It revealed 38 MQTL for FDR (12 diseases) on all chromosomes except chromosome 10. Five MQTL namely 1_4, 2_4, 3_2, 3_4, and 5_4 were linked with multiple FDR. Total of 1910 candidate genes were identified for all the MQTL regions, with protein kinase gene families, TFs, pathogenesis-related, and disease-responsive proteins directly or indirectly associated with FDR. The comparison of physical positions of marker-traits association (MTAs) from genome-wide association studies with genes underlying MQTL interval verified the presence of QTL/candidate genes for particular diseases. The linked markers to MQTL and putative candidate genes underlying identified MQTL can be further validated in the germplasm through marker screening and expression studies. The study also attempted to unravel the underlying mechanism for FDR resistance by analyzing the constitutive gene network, which will be a useful resource to understand the molecular mechanism of defense-response of a particular disease and multiple FDR in maize. [ABSTRACT FROM AUTHOR]