Targeting Genes for Genetic Manipulation in Crop Species

1990 ◽  
pp. 55-76 ◽  
Author(s):  
J. W. Snape ◽  
C. N. Law ◽  
A. J. Worland ◽  
B. B. Parker
Keyword(s):  
Genetic Manipulation ◽  
Crop Species

scholarly journals Genome-scale mining of root-preferential genes from maize and characterization of their promoter activity

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Ye Li ◽  
Xiaoqing Liu ◽  
Rumei Chen ◽  
Jian Tian ◽  
Yunliu Fan ◽  
...  
Keyword(s):  
Genetic Manipulation ◽  
Root Traits ◽  
Crop Productivity ◽  
Data Sets ◽  
Crop Species ◽  
Biotic Stresses ◽  
Maize Cultivars ◽  
Genomic Scale ◽  
Functional Analyses ◽  
Genome Scale

Abstract Background Modification of root architecture and improvement of root resistance to stresses can increase crop productivity. Functional analyses of root-specific genes are necessary for root system improvement, and root-specific promoters enable research into the regulation of root development and genetic manipulation of root traits. Maize is an important crop species; however, little systematic mining of root-specific genes and promoters has been performed to date. Results Genomic-scale mining based on microarray data sets followed by transcript detection resulted in the identification of 222 root-specific genes. Gene Ontology enrichment analyses revealed that these 222 root-specific genes were mainly involved in responses to chemical, biotic, and abiotic stresses. Of the 222 genes, 33 were verified by quantitative reverse transcription polymerase chain reaction, and 31 showed root-preferential activity. About 2 kb upstream 5 of the 31 identified root-preferential genes were cloned from the maize genome as putative promoters and named p8463, p5023, p1534, p8531 and p6629. GUS staining of transgenic maize-derived promoter-GUS constructs revealed that the five promoters drove GUS expression in a root-preferential manner. Conclusions We mined root-preferential genes and their promoters in maize and verified p8463, p5023, p1534, p8531 and p6629 as root-preferential promoters. Our research enables the identification of other tissue-specific genes and promoters in maize and other species. In addition, the five promoters may enable enhancement of target gene(s) of maize in a root-preferential manner to generate novel maize cultivars with resistance to water, fertilizer constraints, or biotic stresses.

scholarly journals Knockout of the HvCKX1 or HvCKX3 Gene in Barley (Hordeum vulgare L.) by RNA-Guided Cas9 Nuclease Affects the Regulation of Cytokinin Metabolism and Root Morphology

Cells ◽  
2019 ◽  
Vol 8 (8) ◽  
pp. 782 ◽  
Author(s):  
Gasparis ◽  
Przyborowski ◽  
Kała ◽  
Nadolska-Orczyk
Keyword(s):  
Grain Yield ◽  
Root Morphology ◽  
Genetic Manipulation ◽  
Root Hairs ◽  
Cytokinin Oxidase ◽  
Cytokinin Metabolism ◽  
Hordeum Vulgare L ◽  
Crop Species ◽  
Grain Yields ◽  
Mutant Lines

Barley is among four of the most important cereal crops with respect to global production. Increasing barley yields to desired levels can be achieved by the genetic manipulation of cytokinin content. Cytokinins are plant hormones that regulate many developmental processes and have a strong influence on grain yield. Cytokinin homeostasis is regulated by members of several multigene families. CKX genes encode the cytokinin oxidase/dehydrogenase enzyme, which catalyzes the irreversible degradation of cytokinin. Several recent studies have demonstrated that the RNAi-based silencing of CKX genes leads to increased grain yields in some crop species. To assess the possibility of increasing the grain yield of barley by knocking out CKX genes, we used an RNA-guided Cas9 system to generate ckx1 and ckx3 mutant lines with knockout mutations in the HvCKX1 and HvCKX3 genes, respectively. Homozygous, transgene-free mutant lines were subsequently selected and analyzed. A significant decrease in CKX enzyme activity was observed in the spikes of the ckx1 lines, while in the ckx3 lines, the activity remained at a similar level to that in the control plants. Despite these differences, no changes in grain yield were observed in either mutant line. In turn, differences in CKX activity in the roots between the ckx1 and ckx3 mutants were reflected via root morphology. The decreased CKX activity in the ckx1 lines corresponded to greater root length, increased surface area, and greater numbers of root hairs, while the increased CKX activity in the ckx3 mutants gave the opposite results. RNA-seq analysis of the spike and root transcriptomes revealed an altered regulation of genes controlling cytokinin metabolism and signaling, as well as other genes that are important during seed development, such as those that encode nutrient transporters. The observed changes suggest that the knockout of a single CKX gene in barley may be not sufficient for disrupting cytokinin homeostasis or increasing grain yields.

scholarly journals Novel Transcriptome Study and Detection of Metabolic Variations in UV-B-Treated Date Palm (Phoenix dactylifera cv. Khalas)

2021 ◽  
Vol 22 (5) ◽  
pp. 2564
Author(s):  
Mohamed Maher ◽  
Hasan Ahmad ◽  
Elsayed Nishawy ◽  
Yufei Li ◽  
Jie Luo
Keyword(s):  
Amino Acids ◽  
Date Palm ◽  
Genetic Manipulation ◽  
Uv Light ◽  
Phoenix Dactylifera ◽  
Crop Species ◽  
Palm Trees ◽  
Fruit Species ◽  
Liquid Chromatography Tandem Mass ◽  
Encoding Genes

Date palm (Phoenix dactylifera) is one of the most widespread fruit crop species and can tolerate drastic environmental conditions that may not be suitable for other fruit species. Excess UV-B stress is one of the greatest concerns for date palm trees and can cause genotoxic effects. Date palm responds to UV-B irradiation through increased DEG expression levels and elaborates upon regulatory metabolic mechanisms that assist the plants in adjusting to this exertion. Sixty-day-old Khalas date palm seedlings (first true-leaf stage) were treated with UV-B (wavelength, 253.7 nm; intensity, 75 μW cm−2 for 72 h (16 h of UV light and 8 h of darkness). Transcriptome analysis revealed 10,249 and 12,426 genes whose expressions were upregulated and downregulated, respectively, compared to the genes in the control. Furthermore, the differentially expressed genes included transcription factor-encoding genes and chloroplast- and photosystem-related genes. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) was used to detect metabolite variations. Fifty metabolites, including amino acids and flavonoids, showed changes in levels after UV-B excess. Amino acid metabolism was changed by UV-B irradiation, and some amino acids interacted with precursors of different pathways that were used to synthesize secondary metabolites, i.e., flavonoids and phenylpropanoids. The metabolite content response to UV-B irradiation according to hierarchical clustering analysis showed changes in amino acids and flavonoids compared with those of the control. Amino acids might increase the function of scavengers of reactive oxygen species by synthesizing flavonoids that increase in response to UV-B treatment. This study enriches the annotated date palm unigene sequences and enhances the understanding of the mechanisms underlying UV-B stress through genetic manipulation. Moreover, this study provides a sequence resource for genetic, genomic and metabolic studies of date palm.

Genetic diversity of maize kernel starch-synthesis genes with SNAPs

Genome ◽  
2006 ◽  
Vol 49 (10) ◽  
pp. 1287-1296 ◽  
Author(s):  
Ji-Hyun Shin ◽  
Soon-Jae Kwon ◽  
Ju Kyong Lee ◽  
Hwang-Kee Min ◽  
Nam-Soo Kim
Keyword(s):  
Genetic Diversity ◽  
Genetic Manipulation ◽  
Starch Synthesis ◽  
Strong Linkage Disequilibrium ◽  
Maize Breeding ◽  
Crop Species ◽  
Single Nucleotide ◽  
Maize Populations ◽  
Improvement Programs ◽  
Selection Of

Measuring genetic diversity in populations of a crop species is very important for understanding the genetic structure of and subsequently improving the crop species by genetic manipulation. Single-nucleotide amplified polymorphisms (SNAPs) among and within maize populations of waxy, dent, and sweet corns at 25 single-nucleotide polymorphism (SNP) sites in 6 kernel starch-synthesis genes (sh2, bt2, su1, ae1, wx1, and sh1) were determined. Because of the intensive selection of some favorable alleles in starch-synthesis genes during the breeding process, and the resultant strong linkage disequilibrium (LD), the number of haplotypes in each population was far less than expected. Subsequent phenetic clustering analysis with the SNAPs indicated that the dent, waxy, and sweet corns formed distinct subclusters, except in a few incidences. LD was surveyed among SNAPs of intragenic, intergenic, and intrachromosomal SNPs in whole and subpopulations, which revealed that some SNAPs showed high LD with many other SNAPs, but some SNAPs showed low or no significant LD with others, depending on the subpopulation, indicating that these starch genes have undergone different selection in each subpopulation during the breeding process. Because the starch synthesis genes used in this study are important in maize breeding, the genetic diversity, LD, and accessions having rare SNAP alleles might be valuable in maize improvement programs.

New Roads to Crop Protection Against Viruses

1994 ◽  
Vol 23 (1) ◽  
pp. 33-39 ◽  
Author(s):  
T. Michael A. Wilson ◽  
Jeffrey W. Davies
Keyword(s):  
Resistance Genes ◽  
Recombinant Dna ◽  
Genetic Manipulation ◽  
Crop Protection ◽  
Natural Resistance ◽  
Crop Species ◽  
Viral Pathogens ◽  
Pests And Diseases ◽  
Breeding Programmes ◽  
Recombinant Dna Techniques

Farmers and growers, already under pressure to produce food under tighter constraints, face the omnipresent threat of new pests and diseases caused by new strains of fungal, bacterial or viral pathogens or their vectors, such as insects. The whitefly Bemisia tabaci is an example of such a threat in Europe (Bedford and Markham, 1993). It is feared that over-use of pesticides, fertilizers and growth regulators could create major environmental problems, but to survive without them will require other strategies, broadly referred to as ‘sustainable agriculture ’. Traditionally, durable disease resistance has required ingenious breeding programmes to introduce natural resistance genes from crop-related wild species into crops. However, we can now exploit the power, flexibility and specificity of recombinant DNA techniques (genetic manipulation) either to identify existing natural resistance genes and transfer them between unrelated crop species, or to create new and more effective resistance genes against one or more pathogens or pests. The rationale behind many of these ‘designer genes ’ has arisen from empirical field observations or from our deeper understanding of molecular and genetical aspects of the natural life-cycle of the pathogen.

Metabolic engineering of CHO cells to prepare glycoproteins

2018 ◽  
Vol 2 (3) ◽  
pp. 433-442 ◽  
Author(s):  
Qiong Wang ◽  
Michael J. Betenbaugh
Keyword(s):  
Metabolic Engineering ◽  
Cho Cells ◽  
Genetic Manipulation ◽  
Chinese Hamster ◽  
Post Translational Modification ◽  
Effector Functions ◽  
Recombinant Glycoproteins ◽  
Production Platform ◽  
Chemical Inhibitors ◽  
Amino Acid Mutations

As a complex and common post-translational modification, N-linked glycosylation affects a recombinant glycoprotein's biological activity and efficacy. For example, the α1,6-fucosylation significantly affects antibody-dependent cellular cytotoxicity and α2,6-sialylation is critical for antibody anti-inflammatory activity. Terminal sialylation is important for a glycoprotein's circulatory half-life. Chinese hamster ovary (CHO) cells are currently the predominant recombinant protein production platform, and, in this review, the characteristics of CHO glycosylation are summarized. Moreover, recent and current metabolic engineering strategies for tailoring glycoprotein fucosylation and sialylation in CHO cells, intensely investigated in the past decades, are described. One approach for reducing α1,6-fucosylation is through inhibiting fucosyltransferase (FUT8) expression by knockdown and knockout methods. Another approach to modulate fucosylation is through inhibition of multiple genes in the fucosylation biosynthesis pathway or through chemical inhibitors. To modulate antibody sialylation of the fragment crystallizable region, expressions of sialyltransferase and galactotransferase individually or together with amino acid mutations can affect antibody glycoforms and further influence antibody effector functions. The inhibition of sialidase expression and chemical supplementations are also effective and complementary approaches to improve the sialylation levels on recombinant glycoproteins. The engineering of CHO cells or protein sequence to control glycoforms to produce more homogenous glycans is an emerging topic. For modulating the glycosylation metabolic pathways, the interplay of multiple glyco-gene knockouts and knockins and the combination of multiple approaches, including genetic manipulation, protein engineering and chemical supplementation, are detailed in order to achieve specific glycan profiles on recombinant glycoproteins for superior biological function and effectiveness.

Drug-Induced Agranulocytosis: A Mini Review

2016 ◽  
Vol 2 (1) ◽  
pp. 57-59
Author(s):  
Pavithra D ◽  
Praveen D ◽  
Vijey Aanandhi M
Keyword(s):  
Bone Marrow ◽  
Complete Blood Count ◽  
Genetic Manipulation ◽  
White Blood Cells ◽  
Deep Infection ◽  
Morbidity Rate ◽  
Drug Induced ◽  
Serious Adverse Event ◽  
Mortality And Morbidity ◽  
The Individual

Agranulocytosis is also known to be granulopenia, causing neutropenia in circulating blood streams .The destruction of white blood cells takes place which leads to increase in the infection rate in an individual where immune system of the individual is suppressed. The symptoms includes fever, sore throat, mouth ulcers. These are commonly seen as adverse effects of a particular drug and are prescribed for the common diagnostic test for regular monitoring of complete blood count in an admitted patient. Drug-induced agranulocytosis remains a serious adverse event due to occurrence of severe sepsis with deep infection leading to pneumonia, septicaemia, and septic shock in two/third of the patient. Antibiotics seem to be the major causative weapon for this disorder. Certain drugs mainly anti-thyroid drugs, ticlopidine hydrochloride, spironolactone, clozapine, antileptic drugs (clozapine), non-steroidal anti-inflammatory agents, dipyrone are the potential causes. Bone marrow insufficiency followed by destruction or limited proliferative bone marrow destruction takes place. Chemotherapy is rarely seen as a causative agent for this disorder. Genetic manipulation may also include as one of the reason. Agranulocytosis can be recovered within two weeks but the mortality and morbidity rate during the acute phase seems to be high, appropriate adjuvant treatment with broad-spectrum antibiotics are prerequisites for the management of complicated neutropenia. Drugs that are treated for this are expected to change as a resistant drug to the patient. The pathogenesis of agranulocytosis is not yet known. A comprehensive literature search has been carried out in PubMed, Google Scholar and articles pertaining to drug-induced agranulocytosis were selected for review.

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