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81.
Cytoplasmic male sterility in sorghum has been reported in a number of varieties originating in different geographical regions (India, Africa and America). We have attempted to characterize three male sterile cytoplasms of Indian origin designated as Maldandi, Guntur and Vizianagaram by studying restriction fragment length polymorphisms (RFLPs) and expression patterns of 14 mitochondrial genes. Our results indicate that the cytoplasms, classified tentatively as Indian A4 types, are distinct from the American A4 and A1 types. Although they are identical to each other with respect to the location of 10 of the mitochondrial genes selected, they can be distinguished from each other on the basis of RFLPs inatp6, atp9 andrrn18. Further the three cytoplasms differ from their maintainers in the location ofnad3, rpsl2 andatpA. Differences are also observed in the pattern of expression ofatpA between all the sterile lines and their respective maintainers. 相似文献
82.
Kaushal Kumar Singh Radhey Shyam Prafullachandra Vishnu Sane 《Photosynthesis research》1996,49(1):11-20
Effect of quality, quantity and minimum duration of light on the process of recovery was investigated in the photoinhibited cells of the green alga Chlamydomonas reinhardtii. Complete and rapid reactivation of photosynthesis took place in diffuse white light of 25 mol m–2 s–1. The recovery was partial (< 10%) in the dark. Far red (725 nm), red (660 nm) and blue light (480 nm) in the range of 10 to 75 mol m–2 s–1 did not enhance the process of reactivation. Photoinhibited cells incubated in dark for 15 min when exposed for 5 min to diffuse light (25 mol m–2 s–1) showed complete reactivation. Even exposure of 15 min dark incubated photoinhibited cells to photoinhibitory light (2500 mol m–2 s–1) for 5 s fully regained the photosynthesis. The study indicated a very precise and triggering effect of light in the process of reactivation. The dark respiratory inhibitor KCN and uncouplers FCCP and CCCP increased the susceptibility of C. reinhardtii to photoinhibition and also prevented photoinhibited cells to reactivate fully even after longer period of incubation under suitable reactivating conditions. Of the various possibilities envisaged to assign the role of dark respiration in recovery process, supply of ATP by mitochondrial respiration appeared sound and pertinent.Abbreviations CCCP-
carbonyl cyanide m-chlorophenylhydrazone
- D1-
32 kDa protein of PS II reaction center
- FCCP-
carbonyl cyanide p-(trifluoromethoxy)phenylhydrazone
- KCN-
potassium cyanide
- PBQ-
phenyl-p-benzoquinone
- PFD-
photon flux density
- SHAM-
salicylhydroxamic acid
NBRI Research Publication No. 431. 相似文献
83.
Prabodh K. Trivedi Pravendra Nath Prafullachandra V. Sane 《Journal of biosciences》1997,22(3):345-355
The photoinhibition of photosynthesis was investigated on intact attached leaves and isolated thylakoid membranes of
Populus deltoides.Our studies demonstrate that in intact leaves photoinhibition takes place under high irradiance which is more pronounced at
higher temperatures. No net loss of Dl and other proteins associated with photosystem II (PSII) were observed even after 64
% photoinhibition suggesting that the degradation of polypeptides associated with PSII is not the only key step responsible
for photoinhibition as observed by other workers. Electron transport studies in isolated thylakoid membranes suggested water
oxidation complex as one of the damaged site during high light exposure. The possible mechanisms of photoinhibition without
net loss of D1 protein are discussed. 相似文献
84.
Andy M. Reynolds Don R. Reynolds Sanjay P. Sane Gao Hu Jason W. Chapman 《Philosophical transactions of the Royal Society of London. Series B, Biological sciences》2016,371(1704)
High-flying insect migrants have been shown to display sophisticated flight orientations that can, for example, maximize distance travelled by exploiting tailwinds, and reduce drift from seasonally optimal directions. Here, we provide a comprehensive overview of the theoretical and empirical evidence for the mechanisms underlying the selection and maintenance of the observed flight headings, and the detection of wind direction and speed, for insects flying hundreds of metres above the ground. Different mechanisms may be used—visual perception of the apparent ground movement or mechanosensory cues maintained by intrinsic features of the wind—depending on circumstances (e.g. day or night migrations). In addition to putative turbulence-induced velocity, acceleration and temperature cues, we present a new mathematical analysis which shows that ‘jerks’ (the time-derivative of accelerations) can provide indicators of wind direction at altitude. The adaptive benefits of the different orientation strategies are briefly discussed, and we place these new findings for insects within a wider context by comparisons with the latest research on other flying and swimming organisms.This article is part of the themed issue ‘Moving in a moving medium: new perspectives on flight’. 相似文献
85.
Manalee Vishnu Surve Anjali Anil Kshama Ganesh Kamath Smita Bhutda Lakshmi Kavitha Sthanam Arpan Pradhan Rohit Srivastava Bhakti Basu Suryendu Dutta Shamik Sen Deepak Modi Anirban Banerjee 《PLoS pathogens》2016,12(9)
Infection of the genitourinary tract with Group B Streptococcus (GBS), an opportunistic gram positive pathogen, is associated with premature rupture of amniotic membrane and preterm birth. In this work, we demonstrate that GBS produces membrane vesicles (MVs) in a serotype independent manner. These MVs are loaded with virulence factors including extracellular matrix degrading proteases and pore forming toxins. Mice chorio-decidual membranes challenged with MVs ex vivo resulted in extensive collagen degradation leading to loss of stiffness and mechanical weakening. MVs when instilled vaginally are capable of anterograde transport in mouse reproductive tract. Intra-amniotic injections of GBS MVs in mice led to upregulation of pro-inflammatory cytokines and inflammation mimicking features of chorio-amnionitis; it also led to apoptosis in the chorio-decidual tissue. Instillation of MVs in the amniotic sac also resulted in intrauterine fetal death and preterm delivery. Our findings suggest that GBS MVs can independently orchestrate events at the feto-maternal interface causing chorio-amnionitis and membrane damage leading to preterm birth or fetal death. 相似文献
86.
InMazus pumilus, all the floral appendages are initiated in acropetal sequence in the second cell layer (except stamens) of the floral primordium
by periclinal divisions. The actinomorphic calyx tube is formed due to zonal growth. The zygomorphy in corolla is evident
from the inception of petal primordia which arise sequentially as independent units in order of one anterior, a pair of anterio-lateral
followed by a pair of posterio-lateral. Later these primordia exhibit differential growth because of which zygomorphy becomes
more pronounced. The upper corolla tube is formed by interprimordial growth and lower corolla tube by zonal growth. Stamens
are initiated in the third layer of the floral apex. Unlike sepals and petals, in the development of stamens (4) underlying
cells of corpus also contribute. Posterior stamen is absent. The stamens become epipetalous because of interprimordial and
zonal growth in the common region below the bases of petals as well as stamens. The two carpel primordia arise as crescent
shaped structures which become continuous due to interprimordial growth. The ovary is formed by a ring of zonal meristem.
The style develops later between stigma and ovary because of intercalary growth. The residual apex grows vertically along
with the ovary and forms the septum of the ovary. All the floral appendages exhibit similar pattern of histogenesis and early
growth suggesting thereby the appendicular nature of these appendages. 相似文献
87.
Alexander G. Ivanov Marianna Krol Prafullachandra Vishnu Sane Youn-Il Park Norman P.A. Huner 《BBA》2007,1767(6):807-813
Comparative lipid analysis demonstrated reduced amount of PG (50%) and lower ratio of MGDG/DGDG in iron-stressed Synechococcus sp. PCC 7942 cells compared to cells grown under iron sufficient conditions. In parallel, the monoenoic (C:1) fatty acids in MGDG, DGDG and PG increased from 46.8%, 43.7% and 45.6%, respectively in control cells to 51.6%, 48.8% and 48.7%, respectively in iron-stressed cells. This suggests increased membrane dynamics, which may facilitate the diffusion of PQ and keep the PQ pool in relatively more oxidized state in iron-stressed compared to control cells. This was confirmed by chlorophyll fluorescence and thermoluminescence measurements. Analysis of carotenoid composition demonstrated that the induction of isiA (CP43′) protein in response to iron stress is accompanied by significant increase of the relative abundance of all carotenoids. The quantity of carotenoids calculated on a Chl basis increased differentially with nostoxanthin, cryptoxanthin, zeaxanthin and β-carotene showing 2.6-, 3.1-, 1.9- and 1.9-fold increases, respectively, while the relative amount of caloxanthin was increased only by 30%. HPLC analyses of the pigment composition of Chl-protein complexes separated by non-denaturating SDS-PAGE demonstrated even higher relative carotenoids content, especially of cryptoxanthin, in trimer and monomer PSI Chl-protein complexes co-migrating with CP43′ from iron-stressed cells than in PSI complexes from control cells where CP43′ is not present. This implies a carotenoid-binding role for the CP43′ protein which supports our previous suggestion for effective energy quenching and photoprotective role of CP43′ protein in cyanobacteria under iron stress. 相似文献
88.
M. Senthil @ Sankar Vishnu Sukumari Nath Muthulekshmi Lajapathy Jeeva 《Archives Of Phytopathology And Plant Protection》2013,46(6):741-746
The occurrence of Cassava tuber rot in regions of Kolli hills, Kollam, and Kottayam of South India, causes major economic loss up to 70% in Cassava production. The disease tuber is characterised by brown watery lesions with foul smell, making it unfit for further use. The sporangia of the pathogen were oval and ellipsoid with a short pedicle. Identification of the isolate from these regions was also confirmed by ribosomal internal transcribed spacer (ITS) of rDNA region. The pathogen was highly aggressive when pathogenicity was tested. Based on morphological, pathogenicity and ITS sequences, the pathogen was identified as Phytophthora palmivora. Development of integrated disease management practices is essential to combat the disease. This is the first report recording the spread of Cassava tuber rot disease in regions of Kolli hills of Tamil Nadu and Kollam and Kottayam, of Kerala. 相似文献
89.
90.
Haijin Tian Christoph Furtmann Florian Lenz Vishnu Srinivasamurthy Uwe T. Bornscheuer Joachim Jose 《Microbial biotechnology》2022,15(8):2235-2249
The application of enzymes as biocatalysts in industrial processes has great potential due to their outstanding stereo-, regio- and chemoselectivity. Using autodisplay, enzymes can be immobilized on the cell surface of Gram-negative bacteria such as Escherichia coli. In the present study, the surface display of an alcohol dehydrogenase (ADH) and a cyclohexanone monooxygenase (CHMO) on E. coli was investigated. Displaying these enzymes on the surface of E. coli resulted in whole-cell biocatalysts accessible for substrates without further purification. An apparent maximal reaction velocity VMAX(app) for the oxidation of cyclohexanol with the ADH whole-cell biocatalysts was determined as 59.9 mU ml−1. For the oxidation of cyclohexanone with the CHMO whole-cell biocatalysts a VMAX(app) of 491 mU ml−1 was obtained. A direct conversion of cyclohexanol to ε-caprolactone, which is a known building block for the valuable biodegradable polymer polycaprolactone, was possible by combining the two whole-cell biocatalysts. Gas chromatography was applied to quantify the yield of ε-caprolactone. 1.12 mM ε-caprolactone was produced using ADH and CHMO displaying whole-cell biocatalysts in a ratio of 1:5 after 4 h in a cell suspension of OD578nm 10. Furthermore, the reaction cascade as applied provided a self-sufficient regeneration of NADPH for CHMO by the ADH whole-cell biocatalyst. 相似文献