scholarly journals Leaf trichomes and foliar chemistry mediate defence against glasshouse thrips; Heliothrips haemorrhoidalis (Bouché) in Rhododendron simsii

2016 ◽  
Vol 43 (12) ◽  
pp. 1170 ◽  
Author(s):  
Alison S. Scott-Brown ◽  
Tom Gregory ◽  
Iain W. Farrell ◽  
Philip C. Stevenson
Keyword(s):  
Leaf Tissue ◽  
Inverse Correlation ◽  
Feeding Damage ◽  
Specific Expression ◽  
Generalist Herbivore ◽  
Rhododendron Simsii ◽  
Plant Parts ◽  
Heliothrips Haemorrhoidalis ◽  
Herbivore Defence ◽  
Growth And Reproduction

Herbivore defence mechanisms are a costly diversion of resources away from growth and reproduction. Thus time-limited and tissue specific expression in critical plant parts is more efficient as defined by optimal defence theory. Surprisingly little is known about Rhododendron herbivore defence but it may be mediated by combined chemical and physical mechanisms. Rhododendron simsii Planch. survives cyclic infestations of a leaf-feeding thrips, Heliothrips haemorrhoidalis (Bouché), which severely damage mature leaves but avoid terminal young leaves suggesting specific, localised defence expression. We examined correlations between the distribution of thrips and feeding damage with density of trichomes and the concentration of the diterpenoid, grayanotoxin I, a compound implicated in but not previously reported to mediate invertebrate defence in Rhododendron. Our data show that as leaves matured the number of thrips and area of feeding damage increased as trichome density and grayanotoxin I concentration decreased, this inverse correlation suggesting trichomes and grayanotoxin I mediate defence in younger leaf tissue. Grayanotoxin I was tested against H. haemorrhoidalis and was toxic to immature life stages and repellent to the adult thrips, reducing numbers of first instars emerging on leaves when applied at ecologically relevant concentrations. This work demonstrates that the pattern of defensive traits in foliage of a species of Rhododendron is key to its ability to tolerate cyclic infestations of a generalist herbivore, effectively conserving vital tissues required for growth and reproduction.

scholarly journals IκBα targeting promotes oxidative stress-dependent cell death

2021 ◽  
Vol 40 (1) ◽  
Author(s):  
Giovanna Carrà ◽  
Giuseppe Ermondi ◽  
Chiara Riganti ◽  
Luisella Righi ◽  
Giulia Caron ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Cell Fate ◽  
Protein Interactions ◽  
In Silico ◽  
Inverse Correlation ◽  
Ros Production ◽  
Gene Encoding ◽  
Specific Expression ◽  
Novel Approach ◽  
Stress Dependent

Abstract Background Oxidative stress is a hallmark of many cancers. The increment in reactive oxygen species (ROS), resulting from an increased mitochondrial respiration, is the major cause of oxidative stress. Cell fate is known to be intricately linked to the amount of ROS produced. The direct generation of ROS is also one of the mechanisms exploited by common anticancer therapies, such as chemotherapy. Methods We assessed the role of NFKBIA with various approaches, including in silico analyses, RNA-silencing and xenotransplantation. Western blot analyses, immunohistochemistry and RT-qPCR were used to detect the expression of specific proteins and genes. Immunoprecipitation and pull-down experiments were used to evaluate protein-protein interactions. Results Here, by using an in silico approach, following the identification of NFKBIA (the gene encoding IκBα) amplification in various cancers, we described an inverse correlation between IκBα, oxidative metabolism, and ROS production in lung cancer. Furthermore, we showed that novel IκBα targeting compounds combined with cisplatin treatment promote an increase in ROS beyond the tolerated threshold, thus causing death by oxytosis. Conclusions NFKBIA amplification and IκBα overexpression identify a unique cancer subtype associated with specific expression profile and metabolic signatures. Through p65-NFKB regulation, IκBα overexpression favors metabolic rewiring of cancer cells and distinct susceptibility to cisplatin. Lastly, we have developed a novel approach to disrupt IκBα/p65 interaction, restoring p65-mediated apoptotic responses to cisplatin due to mitochondria deregulation and ROS-production.

Temperature Effects on Absorption and Translocation of Trifluralin and Methazole in Peanuts

Weed Science ◽  
1972 ◽  
Vol 20 (4) ◽  
pp. 285-289 ◽  
Author(s):  
K. Hawxby ◽  
E. Basler ◽  
P. W. Santelmann
Keyword(s):  
Temperature Effects ◽  
Lateral Root ◽  
Initial Rate ◽  
Lateral Roots ◽  
Leaf Tissue ◽  
Root Tips ◽  
Plant Parts ◽  
Tap Root ◽  
Rate Of Absorption ◽  
Nutrient Solutions

The absorption and translocation of14C-labeled α,α,α-trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine (trifluralin) and 2-(3,4-dichlorophenyl)-4-methyl-1,2,4-oxadiazolidine-3,5-dione methazole from nutrient solutions of various temperatures by(Arachis hypogaeaL. ‘Starr’) seedlings were determined. The accumulation of trifluralin in roots at 24 hr after exposure to trifluralin was greatest at 21 C and decreased at higher temperatures up to 38 C. The amounts of trifluralin translocated and accumulated in hypocotyls, tops, and cotyledons were small but generally increased with temperature. The initial rate of absorption of trifluralin was greater in excised lateral root tips than in tap root tips, but there was a greater accumulation in excised tap roots at 24 hr. The initial rates of absorption were higher for excised lateral roots at high temperatures. Total absorption of trifluralin at equilibrium was not proportional to the initial rates of absorption but was highest at low (21 C) and high (38 C) temperatures for excised lateral roots. The absorption of methazole by roots and translocation to other plant parts increased linearly with temperature, and it tended to accumulate in the mature leaf tissue.

Genomic Organization, Chromatin Structure, and Transcriptional Regulation of the Murine Alpha Hemoglobin Stabilizing Protein (AHSP) Gene.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 3633-3633
Author(s):  
Louis C. Dore ◽  
Christopher R. Vakoc ◽  
Gerd A. Blobel ◽  
Ross C. Hardison ◽  
David M. Bodine ◽  
...  
Keyword(s):  
Chromatin Structure ◽  
Gene Activation ◽  
Inverse Correlation ◽  
Regulatory Elements ◽  
Genomic Region ◽  
Beta Thalassemia ◽  
Syntenic Block ◽  
Coding Region ◽  
Specific Expression

Abstract Alpha Hemoglobin Stabilizing Protein (AHSP, Eraf) is an abundant erythroid protein that binds and stabilizes alpha globin and alpha hemoglobin (Hb). In mice, loss of AHSP causes hemolytic anemia, with elevated levels of reactive oxygen species and Hb precipitation in erythrocytes. Loss of AHSP exacerbates beta thalassemia phenotypes in mice, presumably by enhancing the toxicity of excessive free alpha Hb. Based on these findings, AHSP is a candidate modifier gene for beta thalassemia in humans. No mutations in the AHSP coding region have been identified in patients to date. However, several groups reported an inverse correlation between beta thalassemia severity and erythroid AHSP expression levels, raising the possibility that AHSP is a quantitative trait modifier of beta thalassemia. To address this possibility, it is important to define the mechanisms that control expression of the AHSP gene. Transcripts of murine Ahsp are inducible by GATA-1. The goals of the current studies are to investigate the mechanisms of this induction and to define the DNA domain that regulates the locus. Using phylogenetic comparisons, we identified a hotspot for mammalian chromosomal rearrangement just downstream of the Ahsp gene. This hotspot is located at the end of a syntenic block of approximately 350 kb that is conserved in mammals and likely marks the 3′ end of the gene regulatory domain. We focused our initial functional studies on a 7 kb genomic region bounded at the 5′ (centromeric) end of Ahsp by the nearest adjacent gene, an EST expressed in multiple tissues, and at the 3′ (telomeric) end by the rearrangement hotspot. In transient transfection assays, the Ahsp promoter region conferred erythroid-specific expression to a linked reporter gene. In heterologous cells, GATA-1 transactivated the Ahsp promoter in a dose-dependent fashion. To examine GATA-1 binding and its subsequent effects on the Ahsp gene in vivo, we used G1E-ER4 cells, a GATA-1 null erythroblast line that undergoes terminal erythroid maturation after activation of an estradiol-inducible form of GATA-1. We made several findings with regards to the role of GATA-1 in Ahsp gene regulation. First, GATA-1 and its cofactor, Friend of GATA-1 (FOG-1), bind directly to the Ahsp locus at regions that contain conserved GATA consensus motifs and are predicted to be important erythroid regulatory elements by our bioinformatic studies. Second, GATA-1 induces epigenetic changes in chromatin structure that are associated with gene activation, including formation of a DNase I hypersensitive site, hyperacetylation of histones H3 and H4, and methylation of histone H3 lysine-4. Together, these findings begin to establish the DNA region and mechanisms that control Ahsp transcription, allowing for further studies to map the cis elements responsible for population variations in gene expression.

scholarly journals Can insect egg deposition ‘warn’ a plant of future feeding damage by herbivorous larvae?

2011 ◽  
Vol 279 (1726) ◽  
pp. 101-108 ◽  
Author(s):  
Ivo Beyaert ◽  
Diana Köpke ◽  
Josefin Stiller ◽  
Almuth Hammerbacher ◽  
Kinuyo Yoneya ◽  
...  
Keyword(s):  
Poor Performance ◽  
Feeding Damage ◽  
Insect Feeding ◽  
Insect Eggs ◽  
Phenolic Metabolites ◽  
Sawfly Larvae ◽  
Insect Egg ◽  
Egg Deposition ◽  
Larval Hatching ◽  
Herbivore Defence

Plant anti-herbivore defence is inducible by both insect feeding and egg deposition. However, little is known about the ability of insect eggs to induce defences directed not against the eggs themselves, but against larvae that subsequently hatch from the eggs. We studied how oviposition (OP) by the sawfly Diprion pini on Pinus sylvestris foliage affects the plant's defensive potential against sawfly larvae. Larvae that initiated their development on P. sylvestris twigs on which they hatched from eggs gained less weight and suffered higher mortality than those fed on egg-free twigs. The poor performance of these larvae also affected the next herbivore generation since fecundity of resulting females was lower than that of females which spent their larval development on egg-free pine. Transcript levels of P. sylvestris sesquiterpene synthases ( Ps TPS1, Ps TPS2) were increased by D. pini OP, reached their highest levels just before larval hatching, and decreased when larvae started to feed. However, concentrations of terpenoid and phenolic metabolites presumed to act as feeding deterrents or toxins for herbivores did not change significantly after OP and feeding. Nevertheless, our performance data suggest that insect egg deposition may act to ‘warn’ a plant of upcoming feeding damage by larvae.

scholarly journals Comparison of genomic DNA extraction methods to obtain high DNA quality from barnyard grass (Echinochloa colona)

2020 ◽  
Author(s):  
Romesh Kumar Salgotra ◽  
Bhagirath Singh Chauhan
Keyword(s):  
Essential Oils ◽  
Dna Extraction ◽  
Leaf Tissue ◽  
Extraction Methods ◽  
High Quality ◽  
Time Saving ◽  
Plant Leaf ◽  
Plant Parts ◽  
Molecular Studies ◽  
Leaf Tissues

Abstract Background: The study of weed genomics is important for the effective management of weeds to enhance crop yield. A rapid, inexpensive and high quality DNA extraction is needed for genomic and other molecular studies. Here, we describe the protocols for DNA extraction from two different parts of the Echinochloa colona plant using modified cetyltrimethylammonium bromide (CTAB) and a commercial kit.Results: In the study, it was observed that the DNA extracted from plant leaf tissues and dry seeds with a modified CTAB protocol was of good quality, with no contaminations of polysaccharides and essential oils. Quality of DNA extracted from dry seeds was comparable with that of plant leaves under both protocols. The extracted DNA from both plant parts was successfully amplified by PCR using the EPSPS microsatellite marker. Compared to the protocol of DNA extracted from leaf tissue, dry seeds will save time and other valuable resources. Moreover, the same protocols can be implemented for the extraction of high-quality DNA for molecular studies in other plant species where a large amount of polysaccharides, secondary metabolites and essential oils are present.Conclusions: Modified methods of DNA extraction from dry seeds are efficient and time-saving which can be used in genotypic and other molecular approaches. High-quality DNA can be isolated from plant leaf tissues using modified CTAB and commercial kits, however, DNA extracted from dry seeds will save time and other valuable resources.

Feeding by Cassida rubiginosa (Coleoptera: Chrysomelidae) and the Effects of Defoliation on Growth of Musk Thistles

1990 ◽  
Vol 25 (4) ◽  
pp. 538-547 ◽  
Author(s):  
Bob Cartwright ◽  
Loke T. Kok
Keyword(s):  
Plant Growth ◽  
Leaf Tissue ◽  
Plant Response ◽  
Laboratory Studies ◽  
Feeding Rates ◽  
Temperature Dependent ◽  
Leaf Consumption ◽  
Growth And Reproduction ◽  
Cassida Rubiginosa ◽  
Effect On Growth

Plant response studies were conducted to determine the effects of feeding by Cassida rubiginosa Müller and mechanical defoliation on the growth and reproduction of musk thistle (Carduus thoermeri Weinmann). Mortality of thistles was highest with 75% mechanical defoliation at the rosette stage; defoliation of thistles after bolting had little effect on growth and reproduction. Thistle growth was more adversely affected by multiple than single defoliations, particularly when 50% or more of the leaf tissue was removed. Single defoliation produced little reduction in plant growth except at the 75% level. Defoliation by C. rubiginosa produced effects on thistles that were intermediate to those resulting from 50 and 75% multiple mechanical defoliations, even though only 23% of the leaf tissue was removed. Laboratory studies of leaf consumption showed that C. rubiginosa larvae consumed more thistle leaf tissue as they matured and that their feeding rates were temperature dependent.

scholarly journals Uptake and Partitioning of Nutrients in Blackberry and Raspberry and Evaluating Plant Nutrient Status for Accurate Assessment of Fertilizer Requirements

2015 ◽  
Vol 25 (4) ◽  
pp. 452-459 ◽  
Author(s):  
Bernadine C. Strik ◽  
David R. Bryla
Keyword(s):  
Nutrient Management ◽  
Leaf Tissue ◽  
Nutrient Status ◽  
Sampling Time ◽  
Rubus Idaeus ◽  
Nutrient Concentrations ◽  
Plant Nutrient ◽  
Red Raspberry ◽  
N Accumulation ◽  
Plant Parts

Raspberry and blackberry (Rubus sp.) plantings have a relatively low nutrient requirement compared with many other perennial fruit crops. Knowledge of annual accumulation of nutrients and periods of rapid uptake allows for better management of fertilization programs. Annual total nitrogen (N) accumulation in the aboveground plant ranged from 62 to 110 and 33 to 39 lb/acre in field-grown red raspberry (Rubus idaeus) and blackberry (Rubus ssp. rubus), respectively. Research on the fate of applied 15N (a naturally occurring istope of N) has shown that primocanes rely primarily on fertilizer N for growth, whereas floricane growth is highly dependent on stored N in the over-wintering primocanes, crown, and roots; from 30% to 40% of stored N was allocated to new growth. Plants receiving higher rates of N fertilizer took up more N, often leading to higher N concentrations in the tissues, including the fruit. Reallocation of N from senescing floricanes and primocane leaves to canes, crown, and roots has been documented. Accumulation of other macro- and micronutrients in plant parts usually preceded growth. Primocanes generally contained the highest concentration of most nutrients during the growing season, except calcium (Ca), copper (Cu), and zinc (Zn), which often were more concentrated in roots. Roots typically contained the highest concentration of all nutrients during winter dormancy. Nutrient partitioning varied considerably among elements due to different nutrient concentrations and requirements in each raspberry and blackberry plant part. This difference not only affected the proportion of each nutrient allocated to plant parts, but also the relative amount of each nutrient lost or removed during harvest, leaf senescence, and pruning. Macro- and micronutrient concentrations are similar for raspberry and blackberry fruit, resulting in a similar quantity of nutrient removed with each ton of fruit at harvest; however, yield may differ among cultivars and production systems. Nutrient removal in harvested red raspberry and blackberry fruit ranged from 11 to 18 lb/acre N, 10 to 19 lb/acre potassium (K), 2 to 4 lb/acre phosphorus (P), 1 to 2 lb/acre Ca, and 1 to 4 lb/acre magnesium (Mg). Pruning senescing floricanes in August led to greater plant nutrient losses than pruning in autumn. Primocane leaf nutrient status is often used in nutrient management programs. Leaf nutrient concentrations differ with primocane leaf sampling time and cultivar. In Oregon, the present recommended sampling time of late July to early August is acceptable for floricane-fruiting raspberry and blackberry types, and primocane-fruiting raspberry, but not for primocane-fruiting blackberry, where sampling leaves on primocane branches during the green fruit stage is recommended. Presently published leaf tissue standards appear to be too high for K in primocane-fruiting raspberry and blackberry, which is not surprising since the primocanes are producing fruit at the time of sampling and fruit contain a substantial amount of K.

scholarly journals Distribution and Transport of Foliar Applied Zinc in Pistachio

1999 ◽  
Vol 124 (4) ◽  
pp. 433-436 ◽  
Author(s):  
Qinglong Zhang ◽  
Patrick H. Brown
Keyword(s):  
Binding Capacity ◽  
Leaf Tissue ◽  
Mature Trees ◽  
Limited Mobility ◽  
Plant Parts ◽  
High Binding ◽  
Total Percentage

The distribution and transport of foliar applied Zn were determined for pistachio (Pistachio vera L.) seedlings and mature trees using stable 68Zn isotope. In seedlings, ≈5.4% of Zn adsorbed by the leaf was transported out of the treated leaves and this Zn was detected in all other plant parts to varying extent. In mature trees, the transport of Zn occurred both acropetally and basipetally within the leaflets with more basipetal movement; however, no significant amount of Zn was transported out of the treated leaflets during the first 10 days after application. The total percentage of Zn transported to other plant parts 20 days after application was significantly greater when Zn was applied to immature leaflets (6.5%) than to mature leaflets (2.1%), though the majority of the absorbed Zn remained within the treated leaflets. The limited mobility of foliar-absorbed Zn in pistachio may partially be attributed to the high binding capacity of leaf tissue for Zn.

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