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"Slade, Ann"
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Korgi. Book 4
Magic potions can be powerful stuff, but they don't always turn out like you want. Our canine hero, Sprout the Korgi, learns this the hard way - and goes through quite the transformation - in his latest adventure! This mixed-up woodland fairy tale features Ivy's first meeting with Sprout, a surprisingly musical new trick, an undead unicorn, more of those pesky Creephogs, and at least one giant boulder. As always, the story unfolds in lovingly detailed pen-and-ink drawings. From the heart, mind, and hands of Christian Slade comes the most fantastic and creative chapter yet from the enchanting world of Korgi.
Book
Development of high amylose wheat through TILLING
Background
Wheat (
Triticum spp.)
is an important source of food worldwide and the focus of considerable efforts to identify new combinations of genetic diversity for crop improvement. In particular, wheat starch composition is a major target for changes that could benefit human health. Starches with increased levels of amylose are of interest because of the correlation between higher amylose content and elevated levels of resistant starch, which has been shown to have beneficial effects on health for combating obesity and diabetes. TILLING (Targeting Induced Local Lesions in Genomes) is a means to identify novel genetic variation without the need for direct selection of phenotypes.
Results
Using TILLING to identify novel genetic variation in each of the A and B genomes in tetraploid durum wheat and the A, B and D genomes in hexaploid bread wheat, we have identified mutations in the form of single nucleotide polymorphisms (SNPs) in starch branching enzyme IIa genes (SBEIIa). Combining these new alleles of SBEIIa through breeding resulted in the development of high amylose durum and bread wheat varieties containing 47-55% amylose and having elevated resistant starch levels compared to wild-type wheat. High amylose lines also had reduced expression of SBEIIa RNA, changes in starch granule morphology and altered starch granule protein profiles as evaluated by mass spectrometry.
Conclusions
We report the use of TILLING to develop new traits in crops with complex genomes without the use of transgenic modifications. Combined mutations in SBEIIa in durum and bread wheat varieties resulted in lines with significantly increased amylose and resistant starch contents.
Journal Article
Korgi
Woodland fantasy about a young girl, Ivy, her Korgi, Sprout, and their adventures in Korgi Hollow.
Book
Development of non-transgenic glyphosate tolerant wheat by TILLING
Glyphosate (N-phosphonomethyl-glycine) is the world’s most widely used broad spectrum, post-emergence herbicide. It inhibits the chloroplast-targeted enzyme 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS; EC 2.5.1.19), a component of the plant and microorganism-specific shikimate pathway and a key catalyst in the production of aromatic amino acids. Variants of EPSPS that are not inhibited by glyphosate due to particular amino acid alterations in the active site of the enzyme are known. Some of these variants have been identified in weed species that have developed resistance to glyphosate because of the strong selective pressure of continuous, heavy glyphosate use. We have used TILLING (Targeting Induced Local Lesions in Genomes), a non-transgenic, target-selected, reverse genetics, mutation breeding technique, and conventional genetic crosses, to identify and combine, through two rounds of mutagenesis, wheat lines having both T
102
I and P
106
S (so-called TIPS enzyme) mutations in both the A and the D sub-genome homoeologous copies of the wheat EPSPS gene. The combined effects of the T
102
I and P
106
S mutations are known from previous work in multiple species to minimize the binding of the herbicide while maintaining the affinity of the catalytic site for its native substrates. These novel wheat lines exhibit substantial tolerance to commercially relevant levels of glyphosate.
Journal Article
reverse genetic, nontransgenic approach to wheat crop improvement by TILLING
We report the use of TILLING (targeting induced local lesions in genomes), a reverse genetic, nontransgenic method, to improve a quality trait in a polyploid crop plant.
Waxy
starches, composed mostly of amylopectin, have unique physiochemical properties. Wheat with only one or two functional
waxy
genes (granule-bound starch synthase I, or GBSSI) produces starch with intermediate levels of amylopectin. We have identified 246 alleles of the
waxy
genes by TILLING each homoeolog in 1,920 allohexaploid and allotetraploid wheat individuals. These alleles encode
waxy
enzymes ranging in activity from near wild type to null, and they represent more genetic diversity than had been described in the preceding 25 years. A line of bread wheat containing homozygous mutations in two
waxy
homoeologs created through TILLING and a preexisting deletion of the third
waxy
homoeolog displays a near-null
waxy
phenotype. This approach to creating and identifying genetic variation shows potential as a tool for crop improvement.
Journal Article
Divergent functions of orthologous NAC transcription factors in wheat and rice
The wheat
GPC
-
B1
gene located on chromosome 6B is an early regulator of senescence and affects remobilization of protein and minerals to the grain.
GPC
-
B1
is a NAC transcription factor and has a paralogous copy on chromosome 2B in wheat,
GPC
-
B2
. The closest rice homolog to both wheat
GPC
genes is
Os07g37920
which is located on rice chromosome 7 and is colinear with
GPC
-
B2
. Since rice is a diploid species with a sequenced genome, we initiated the study of
Os07g37920
to develop a simpler model to study senescence and mineral remobilization in cereals. We developed eleven independent RNA interference transgenic rice lines (
Os07g37920
-
RNAi
) and 10 over-expressing transgenic lines (
Os07g37920
-
OE
), but none of them showed differences in senescence. Transgenic
Os07g37920
-
RNAi
rice plants had reduced proportions of viable pollen grains and were male-sterile, but were able to produce seeds by cross pollination. Analysis of the flower morphology of the transgenic rice plants showed that anthers failed to dehisce. Transgenic
Os07g37920
-
OE
lines showed no sterility or anther dehiscence problems.
Os07g37920
transcript levels were higher in stamens compared to leaves and significantly reduced in the transgenic
Os07g37920
-
RNAi
plants. Wheat
GPC
genes showed the opposite transcription profile (higher transcript levels in leaves than in flowers) and plants carrying knock-out mutations of all
GPC
-
1
and
GPC
-
2
genes exhibited delayed senescence but normal anther dehiscence and fertility. These results indicate a functional divergence of the homologous wheat and rice
NAC
genes and suggest the need for separate studies of the function and targets of these transcription factors in wheat and rice.
Journal Article
TILLING moves beyond functional genomics into crop improvement
Transgenic methods have been successfully applied to trait improvement in a number of crops. However, reverse genetics studies by transgenic means are not practical in many commercially important crops, hampering investigations into gene function and the development of novel and improved cultivars. A nontransgenic method for reverse genetics called Targeting Induced Local Lesions IN Genomes (TILLING) has been developed as a method for inducing and identifying novel genetic variation, and has been demonstrated in the model plant, Arabidopsis thaliana. Recently, TILLING has been extended to the improvement of crop plants and shows great promise as a general method for both functional genomics and modulation of key traits in diverse crops.
Journal Article
Patient inclusion in goal setting during early inpatient rehabilitation after acquired brain injury
Objective: To investigate the effects of patient participation in multidisciplinary goal setting during early inpatient rehabilitation after acquired brain injury.
Design: Case controlled retrospective study.
Setting: Regional neurological rehabilitation unit.
Subjects: One hundred and five patients with acquired brain injury.
Main measures: Numbers of goals set and achieved per patient before and after intervention; Barthel Index and Functional Independence Measure.
Results: The intervention resulted in a significant increase in the number of goals set per patient (340 versus 411 total goals, mean per patient 6.3 pre versus 8.05 post, P = 0.008). More patients had multiple goals set within each domain (P = 0.023). There was an increase in the number of patients with sleeping (0 pre, 9 post), continence (3 pre, 17 post) and leisure (15 pre, 35 post) goals set, and leisure goals achieved (60% pre and 68% post, P < 0.001). Correlations between goal achievement and change in activity-related outcome measures (Barthel Index and Functional Independence Measure) also improved with the new goal setting process. The proportion of goals achieved remained similar (60% pre and 63% post intervention), suggesting there was no evidence of inappropriate or unachievable goals set when the patient and family were included.
Conclusions: Real-time engagement of brain-injured patients in the goal setting process during early inpatient rehabilitation is achievable, but requires a structured multidisciplinary assessment of need. We found it increases the number of domains in which goals are set and includes functional areas not rated by commonly used global measures of outcome during inpatient rehabilitation.
Journal Article
Functional characterization of GPC-1 genes in hexaploid wheat
In wheat, monocarpic senescence is a tightly regulated process during which nitrogen (N) and micronutrients stored pre-anthesis are remobilized from vegetative tissues to the developing grains. Recently, a close connection between senescence and remobilization was shown through the map-based cloning of the GPC (grain protein content) gene in wheat. GPC-B1 encodes a NAC transcription factor associated with earlier senescence and increased grain protein, iron and zinc content, and is deleted or non-functional in most commercial wheat varieties. In the current research, we identified ‘loss of function’ ethyl methanesulfonate mutants for the two GPC-B1 homoeologous genes; GPC-A1 and GPC-D1, in a hexaploid wheat mutant population. The single gpc-a1 and gpc-d1 mutants, the double gpc-1 mutant and control lines were grown under field conditions at four locations and were characterized for senescence, GPC, micronutrients and yield parameters. Our results show a significant delay in senescence in both the gpc-a1 and gpc-d1 single mutants and an even stronger effect in the gpc-1 double mutant in all the environments tested in this study. The accumulation of total N in the developing grains showed a similar increase in the control and gpc-1 plants until 25 days after anthesis (DAA) but at 41 and 60 DAA the control plants had higher grain N content than the gpc-1 mutants. At maturity, GPC in all mutants was significantly lower than in control plants while grain weight was unaffected. These results demonstrate that the GPC-A1 and GPC-D1 genes have a redundant function and play a major role in the regulation of monocarpic senescence and nutrient remobilization in wheat.
Journal Article