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Ameziane, Rafiqa; Bernhard, K; Lightfoot, David A.

doi:10.1023/a:1004794000267

Cited by 112 publications

(18 citation statements)

References 35 publications

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“…However, this was not reliably reproduced under field conditions (Thomsen et al, 2014). Constitutive expression of GDH from Escherichia coli and Aspergillus in tobacco and rice respectively resulted in biomass and seed size increases (Ameziane et al, 2000; Abiko et al, 2010). However, when two GDH genes from Nicotiana plumbaginifolia were expressed in tobacco, overall biomass was decreased (Terce-Laforgue et al, 2013).…”

Section: Introductionmentioning

confidence: 99%

Whole Genome Sequencing Reveals Potential New Targets for Improving Nitrogen Uptake and Utilization in Sorghum bicolor

Massel

Campbell

Mace³

et al. 2016

Front. Plant Sci.

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Nitrogen (N) fertilizers are a major agricultural input where more than 100 million tons are supplied annually. Cereals are particularly inefficient at soil N uptake, where the unrecovered nitrogen causes serious environmental damage. Sorghum bicolor (sorghum) is an important cereal crop, particularly in resource-poor semi-arid regions, and is known to have a high NUE in comparison to other major cereals under limited N conditions. This study provides the first assessment of genetic diversity and signatures of selection across 230 fully sequenced genes putatively involved in the uptake and utilization of N from a diverse panel of sorghum lines. This comprehensive analysis reveals an overall reduction in diversity as a result of domestication and a total of 128 genes displaying signatures of purifying selection, thereby revealing possible gene targets to improve NUE in sorghum and cereals alike. A number of key genes appear to have been involved in selective sweeps, reducing their sequence diversity. The ammonium transporter (AMT) genes generally had low allelic diversity, whereas a substantial number of nitrate/peptide transporter 1 (NRT1/PTR) genes had higher nucleotide diversity in domesticated germplasm. Interestingly, members of the distinct race Guinea margaritiferum contained a number of unique alleles, and along with the wild sorghum species, represent a rich resource of new variation for plant improvement of NUE in sorghum.

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Section: Introductionmentioning

confidence: 99%

Whole Genome Sequencing Reveals Potential New Targets for Improving Nitrogen Uptake and Utilization in Sorghum bicolor

Massel

Campbell

Mace³

et al. 2016

Front. Plant Sci.

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“…Efforts have focused on (1) transgenes targeting N uptake and transport, such as ammonium transporters [37], proton gradient-forming ATPases [38], or peptide/nitrate transporters [39]; (2) transgenes directly involved in primary N metabolism such as cytosolic glutamine synthetase (GS1;1 and GS1;2) [40,41,42], plastidic glutamine synthetase (GS2) [43], glutamate synthase (GOGAT) [44], glutamate dehydrogenase (GDH, [45] or primary and secondary N metabolism such as transaminases like asparagine synthetase (AS1) [46] and alanine aminotransferase (AlaAT) [12]; (3) transgenes involved in N recycling such as autophagy-related factor 8c (ATG8c, [47]); (4) regulatory factors such as the transcription factor Dof1 [48,49], microRNA826 [50], or microRNA444 [51]; (5) or N-responsive transgenes of unknown function such as the early nodulin 93-like gene [52]. Although there have not been any detailed metabolomics studies involving plants with genetically engineered NUE phenotypes, several studies have examined specific metabolite levels, some of these studies are listed in Table 2 [12,41,46,48,49,52,53,54]).…”

Section: Discussionmentioning

confidence: 99%

Understanding Plant Nitrogen Metabolism through Metabolomics and Computational Approaches

Beatty

Klein

Fischer

et al. 2016

Plants

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A comprehensive understanding of plant metabolism could provide a direct mechanism for improving nitrogen use efficiency (NUE) in crops. One of the major barriers to achieving this outcome is our poor understanding of the complex metabolic networks, physiological factors, and signaling mechanisms that affect NUE in agricultural settings. However, an exciting collection of computational and experimental approaches has begun to elucidate whole-plant nitrogen usage and provides an avenue for connecting nitrogen-related phenotypes to genes. Herein, we describe how metabolomics, computational models of metabolism, and flux balance analysis have been harnessed to advance our understanding of plant nitrogen metabolism. We introduce a model describing the complex flow of nitrogen through crops in a real-world agricultural setting and describe how experimental metabolomics data, such as isotope labeling rates and analyses of nutrient uptake, can be used to refine these models. In summary, the metabolomics/computational approach offers an exciting mechanism for understanding NUE that may ultimately lead to more effective crop management and engineered plants with higher yields.

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“…Furthermore, corn and tobacco plants transformed with the gdhA gene are resistant to root rot following Fusarium virguliforme infection. Previously, it has been shown that tobacco plants transformed with the gdhA gene show an increased level of resistance to the herbicide glufosinate [35] and that total free amino acids were increased in these plants [36,37]. …”

Section: Discussionmentioning

confidence: 99%

Down-regulation of acetolactate synthase compromises Ol-1- mediated resistance to powdery mildew in tomato

Gao¹,

Huibers

Loonen³

et al. 2014

BMC Plant Biol

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BackgroundIn a cDNA-AFLP analysis comparing transcript levels between powdery mildew (Oidium neolycopersici)-susceptible tomato cultivar Moneymaker (MM) and near isogenic lines (NILs) carrying resistance gene Ol-1 or Ol-4, a transcript-derived fragment (TDF) M11E69-195 was found to be present in NIL-Ol-1 but absent in MM and NIL-Ol-4. This TDF shows homology to acetolactate synthase (ALS). ALS is a key enzyme in the biosynthesis of branched-chain amino acids valine, leucine and isoleucine, and it is also a target of commercial herbicides.ResultsThree ALS homologs ALS1, ALS2, ALS3 were identified in the tomato genome sequence. ALS1 and ALS2 show high similarity, whereas ALS3 is more divergent. Transient silencing of both ALS1 and ALS2 in NIL-Ol-1 by virus-induced gene silencing (VIGS) resulted in chlorotic leaf areas that showed increased susceptibility to O. neolycopersici (On). VIGS results were confirmed by stable transformation of NIL-Ol-1 using an RNAi construct targeting both ALS1 and ALS2. In contrast, silencing of the three ALS genes individually by RNAi constructs did not compromise the resistance of NIL-Ol-1. Application of the herbicide chlorsulfuron to NIL-Ol-1 mimicked the VIGS phenotype and caused loss of its resistance to On. Susceptible MM and On-resistant line NIL-Ol-4 carrying a nucleotide binding site and leucine rich repeat (NB-LRR) resistance gene were also treated with chlorsulfuron. Neither the susceptibility of MM nor the resistance of NIL-Ol-4 was affected.ConclusionsALS is neither involved in basal defense, nor in resistance conferred by NB-LRR type resistance genes. Instead, it is specifically involved in Ol-1-mediated resistance to tomato powdery mildew, suggesting that ALS-induced change in amino acid homeostasis is important for resistance conferred by Ol-1.

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Cited by 112 publications

References 35 publications

Whole Genome Sequencing Reveals Potential New Targets for Improving Nitrogen Uptake and Utilization in Sorghum bicolor

Whole Genome Sequencing Reveals Potential New Targets for Improving Nitrogen Uptake and Utilization in Sorghum bicolor

Understanding Plant Nitrogen Metabolism through Metabolomics and Computational Approaches

Down-regulation of acetolactate synthase compromises Ol-1- mediated resistance to powdery mildew in tomato

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