Helicoverpa armigera (Lepidoptera: Noctuidae) and other polyphagous agricultural pests are extending their plant host range and emerging as serious agents in restraining crop productivity. Dynamic ...regulation, coupled with a diversity of digestive and detoxifying enzymes, play a crucial role in the adaptation of polyphagous insects. To investigate the functional intricacy of serine proteases in the development and polyphagy of H. armigera, we profiled the expression of eight trypsin‐like and four chymotrypsin‐like phylogenetically diverse mRNAs from different life stages of H. armigera reared on nutritionally distinct host plants. These analyses revealed diet‐ and stage‐specific protease expression patterns. The trypsins expressed showed structural variations, which might result in differential substrate specificity and interaction with inhibitors. Protease profiles in the presence of inhibitors and their mass spectrometric analyses revealed insight into their differential activity. These findings emphasize the differential expression of serine proteases and their consequences for digestive physiology in promoting polyphagy in H. armigera.
Developmental patterns and survival of the cotton bollworm, Helicoverpa armigera Hübner (Lepidoptera: Noctuidae), a polyphagous insect pest, have been studied with reference to the effect of diet on ...major gut digestive enzymes (amylases, proteases, and lipases). Significant correlations between nutritional quality of the diet and larval and pupal mass were observed when H. armigera larvae were fed on various host plants viz. legumes (chickpea and pigeonpea), vegetables (tomato and okra), flowers (rose and marigold), and cereals (sorghum and maize). Larvae fed on diets rich in proteins and/or carbohydrates (pigeonpea, chickpea, maize, and sorghum) showed higher larval mass and developed more rapidly than larvae fed on diets with low protein and carbohydrate content (rose, marigold, okra, and tomato). Low calorific value diets like rose and marigold resulted in higher mortality (25–35%) of H. armigera. Even with highly varying development efficiency and larval/pupal survival rates, H. armigera populations feeding on different diets completed their life cycles. Digestive enzymes of H. armigera displayed variable expression levels and were found to be regulated on the basis of macromolecular composition of the diet. Post—ingestive adaptations operating at the gut level, in the form of controlled release of digestive enzymes, might be a key factor contributing to the physiological plasticity in H. armigera.
Novel forms of Pin-II type proteinase inhibitor (PIs) cDNAs (
CanPIs) having three or four inhibitory repeat domains (IRD) were isolated from the developing green fruits of
Capsicum annuum. Deduced ...amino acid (aa) sequences of the
CanPIs showed up to 15% sequence divergence among each other or reported inhibitors (
CanPI-1
AF039398,
CanPI-2
AF221097). Amino acid sequence analysis of these CanPIs revealed that three IRD PIs have trypsin inhibitory sites, while four IRD CanPIs have both trypsin and chymotrypsin inhibitory sites. Four
CanPIs, two having three IRD (
CanPI-3
AY986465 and
CanPI-5
DQ005912) and two having four IRD (
CanPI-7
DQ005913 and
CanPI-9
DQ005915), were cloned in
Pichia pastoris to express recombinant CanPIs. Recombinant CanPIs inhibited 90% of bovine trypsin (TI), while chymotrypsin inhibition (CI) varied with the number of chymotrypsin inhibitory sites in the CanPIs. Recombinant inhibitors inhibited over 70% of the gut proteinase activity of
Helicoverpa armigera.
H. armigera larvae fed on recombinant CanPIs individually incorporated into artificial diet, showed 35% mortality; in addition, weight gain in
H. armigera larvae and pupae was severely reduced compared to controls. Of the four CanPIs, CanPI-7, which has two sites for TI and CI, was the only one to have a consistently antagonistic effect on
H. armigera growth and development. We conclude that among the four recombinant PIs tested, CanPIs containing diverse IRDs are best suited for developing insect-resistant transgenic plants.
Midgut digestive amylases and proteinases of
Helicoverpa armigera, a polyphagous and devastating insect pest of economic importance have been studied. We also identified the potential of a sorghum ...amylase inhibitor against
H. armigera midgut amylase. Amylase activities were detected in all the larval instars, pupae, moths and eggs; early instars had lower amylase levels which steadily increased up to the sixth larval instar. Qualitative and quantitative differences in midgut amylases of
H. armigera upon feeding on natural and artificial diets were evident. Natural diets were categorized as one or more members of legumes, vegetables, flowers and cereals belonging to different plant families. Amylase activity and isoform patterns varied depending on host plant and/or artificial diet. Artificial diet-fed
H. armigera larvae had comparatively high amylase activity and several unique amylase isoforms. Correlation of amylase and proteinase activities of
H. armigera with the protein and carbohydrate content of various diets suggested that
H. armigera regulates the levels of these digestive enzymes in response to macromolecular composition of the diet. These adjustments in the digestive enzymes of
H. armigera may be to obtain better nourishment from the diet and avoid toxicity due to nutritional imbalance.
H. armigera, a generalist feeder experiences a great degree of nutritional heterogeneity in its diet. An investigation of the differences in enzyme levels in response to macronutrient balance and imbalance highlight their importance in insect nutrition.
Two proteinase inhibitors (PIs), CapA1 and CapA2, were purified from
Capsicum annum Linn. Var.
Phule Jyoti leaves and assessed for their in vitro and in vivo activity against
Helicoverpa armigera gut ...proteinases (HGPs). Both the inhibitors exhibited molecular weights of about 12 kDa with inhibitory activity against bovine trypsin and chymotrypsin indicating presence of probable two-inhibitor repeats of PIN II family. CapA1 and CapA2 inhibited 60–80% HGP (azocaseinolytic) activity of fourth instar larvae feeding on various host plants while 45–65% inhibition of HGP activity of various instars (II to VI) larvae reared on artificial diet. The partial purification of HGP isoforms, their characterization with synthetic inhibitors and inhibition by
C. annum PIs revealed that most of the trypsin-like activity (68–91%) of HGPs was sensitive to
C. annum PIs while 39–85% chymotrypsin-like activity of HGPs was insensitive to these inhibitors. The feeding of
C. annum leaf extracts and two purified PIs in various doses to
H. armigera larvae for two successive generations through artificial diet demonstrated their potential in inhibiting larval growth and development, delay in pupation period and dramatic reduction in fecundity and fertility. This is the first report-demonstrating efficacy of
C. annum PIs against insect gut proteinases as well as larval growth and development of
H. armigera.
We analyze Chandra observations of the hot atmospheres of 40 early spiral and elliptical galaxies. Using new temperature, density, cooling time, and mass profiles, we explore relationships between ...their hot atmospheres and cold molecular gas. Molecular gas mass correlates with atmospheric gas mass and density over four decades from central galaxies in clusters to normal giant ellipticals and early spirals. The mass and density relations follow power laws: and , respectively, at 10 kpc. The ratio of molecular gas to atmospheric gas within a 10 kpc radius lies between 3% and 10% for early-type galaxies and between 3% and 50% for central galaxies in clusters. Early-type galaxies have detectable levels of molecular gas when their atmospheric cooling times fall below ∼1 Gyr at a radius of 10 kpc. A similar trend is found in central cluster galaxies. We find no relationship between the ratio of the cooling time to free-fall time, tc/tff, and the presence or absence of molecular clouds in early-type galaxies. The data are consistent with much of the molecular gas in early-type galaxies having condensed from their hot atmospheres.
Pin-II type proteinase inhibitor (PI) genes were cloned from fruit and stem tissues of
Capsicum annuum L. var Phule Jyoti using primers designed from reported
CanPI gene sequence (
AF039398). In ...total, 21 novel
CanPIs, members of the Pin-II PI family, were identified in the study, with three isoforms of 1-inhibitory repeat domain (IRD), eight isoforms of 2-IRD, three isoforms of 3-IRD, five isoforms of 4-IRD and two partial
CanPI sequences. Most of the sequences showed variation (2 to 20%) in the deduced AA sequences which were pronounced close to the reactive site loop. Expression patterns of
CanPIs in the fruit and stem tissues of mature
C. annuum plants were shown to vary qualitatively and quantitatively using semi-quantitative RT-PCR expression analysis. In the fruit tissue,
CanPIs with different IRDs (from 1 to 4) were expressed simultaneously. In stem tissue, 1- and 2-IRD
CanPIs were strongly expressed along moderate expression of 3- and 4-IRD genes. Analysis of CanPI protein activity showed a range of active forms across the tissues.
CanPI expression was differentially up-regulated upon wounding and insect attack. Although infestation by aphids (
Myzus persicae) and lepidopteran pests (
Spodoptera litura) specifically induced 4-IRD
CanPIs, virus-infected leaves did not affect
CanPI expression. Analysis of CanPI protein activity indicated that the up-regulation in
CanPI expression was not always correlated with increase in PI activity. Our results demonstrated that
CanPI expression is regulated spatially, temporally as well as qualitatively and quantitatively.
Abstract
H
elicoverpa armigera
(
L
epidoptera:
N
octuidae) and other polyphagous agricultural pests are extending their plant host range and emerging as serious agents in restraining crop ...productivity. Dynamic regulation, coupled with a diversity of digestive and detoxifying enzymes, play a crucial role in the adaptation of polyphagous insects. To investigate the functional intricacy of serine proteases in the development and polyphagy of
H
. armigera
, we profiled the expression of eight trypsin‐like and four chymotrypsin‐like phylogenetically diverse
mRNAs
from different life stages of
H
. armigera
reared on nutritionally distinct host plants. These analyses revealed diet‐ and stage‐specific protease expression patterns. The trypsins expressed showed structural variations, which might result in differential substrate specificity and interaction with inhibitors. Protease profiles in the presence of inhibitors and their mass spectrometric analyses revealed insight into their differential activity. These findings emphasize the differential expression of serine proteases and their consequences for digestive physiology in promoting polyphagy in
H
. armigera
.
ABSTRACT
Molecular gas flows are analysed in 14 cluster galaxies (BCGs) centred in cooling hot atmospheres. The BCGs contain $10^{9}\!-\!10^{11}~\rm M_\odot$ of molecular gas, much of which is being ...moved by radio jets and lobes. The molecular flows and radio jet powers are compared to molecular outflows in 45 active galaxies within z < 0.2. We seek to understand the relative efficacy of radio, quasar, and starburst feedback over a range of active galaxy types. Molecular flows powered by radio feedback in BCGs are ∼10–1000 times larger in extent compared to contemporary galaxies hosting quasar nuclei and starbursts. Radio feedback yields lower flow velocities but higher momenta compared to quasar nuclei, as the molecular gas flows in BCGs are usually ∼10–100 times more massive. The product of the molecular gas mass and lifting altitude divided by the AGN or starburst power – a parameter referred to as the lifting factor – exceeds starbursts and quasar nuclei by 2–3 orders of magnitude, respectively. When active, radio feedback is generally more effective at lifting gas in galaxies compared to quasars and starburst winds. The kinetic energy flux of molecular clouds generally lies below and often substantially below a few per cent of the driving power. We find tentatively that star formation is suppressed in BCGs relative to other active galaxies, perhaps because these systems rarely form molecular discs that are more impervious to feedback and are better able to promote star formation.
People with diabetes often live with other chronic conditions and lead complicated lives. Determining what is the best management decision for a patient requires consideration of each individual's ...personal, social and biomedical context, what he or she values, the reasons he or she has to value the available options, and the relative contribution of each option in terms of benefits, harms, costs and inconveniences. Empathic conversations between patients and clinicians to diagnose the patient situation that necessitates action and the range of evidence‐based actions that best address the situation, so‐called shared decision‐making, are essential to the personalized care of people with diabetes. The aim of the present review was to present key elements of shared decision‐making and propose three different approaches for its application. The first approach focuses on transferring information to patients so that they can make decisions. The second approach, choice, focuses on cultivating the individual's ability to give voice to which choice is best for them. The third approach, conversation, establishes an empathic conversational environment through which the individual with diabetes and their clinician think and talk through how to address the problems of living with diabetes and related illnesses. These approaches are manifest in the design of evidence‐based decision aids created to support shared decision‐making. In randomized trials, decision aids can efficiently improve patient's knowledge, satisfaction, risk awareness, decisional conflict and involvement. Further research, however, is needed to better understand when and how to promote the empathic conversations, patient, clinician and service and policy contexts necessary to routinely implement shared decision‐making in different at scale healthcare systems. In the interim, sufficient evidence and tools exist for persons with diabetes and their clinicians to gain expertise in making decisions together.
What's new?
As a tool in the co‐management of diabetes, shared decision‐making offers patients and clinicians a means of determining what is best for the person living with diabetes.
Three shared‐decision‐making approaches are described: 1) the information approach, which focuses on the information that patients and clinicians need; 2) the choice approach, which emphasizes expressing the individual's values and preferences; and 3) the conversation approach, which centres on establishing empathic conversations in which patients and clinicians can together think and talk through how to address the problems of living with diabetes and its comorbidities (i.e. context).
Decision aids are evidence‐based tools (e.g. web‐based, pamphlets, videos or cards) that facilitate a shared‐decision‐making approach to occur, be it information, choice or conversation.
In people with diabetes, randomized trials have tested, with favourable results, decision aids in urban, rural, academic and non‐academic clinical settings.
Uncertainty remains about how best to account for people's life with diabetes, their capacity and interest in the decision‐making process, the skills needed to communicate and engage with patients, and the sustainability, best practices and cost‐effectiveness of large‐scale current implementations of shared decision‐making. The downstream consequences of shared decision‐making also remain unclear.
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