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1.
Plant Physiol Biochem ; 208: 108500, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38513518

RESUMEN

BREVIS RADIX (BRX) is a small plant-specific and evolutionary conserved gene family with divergent yet partially redundant biological functions including root and shoot growth, stomatal development and tiller angle in plants. We characterized a BRX family gene from wheat (Triticum aestivum) by gain-of-function in Arabidopsis. Overexpression of TaBRXL2A resulted in longer primary roots with increased root meristem size and higher root growth under control and exogenous hormone treatments as compared to wild type (Col-0) plants. Overexpression lines also exhibited significant differences with the wild type such as increased rosette size, higher leaf number and leaf size. At reproductive stage, overexpression lines exhibited wider siliques and higher grain weight per plant. Under drought stress, overexpression lines exhibited enhanced drought tolerance in terms of higher chlorophyll retention and lower oxidative stress, thereby leading to significant recovery from drought stress. The analysis suggests that the inherent lower stomatal density in the leaves of overexpression lines and higher stomatal closure in response to ABA might contribute to lower water loss from the overexpression lines. Furthermore, TaBRXL2A protein showed membrane localization, presence of conserved residues at N-terminal for palmitoylation, and phosphosites in the linker region which are prescribed for its potential role in protophloem differentiation and stomatal lineage. Thus, we identified a TaBRX family gene which is involved in developmental pathways essential for plant growth, and also enhances drought tolerance in Arabidopsis.


Asunto(s)
Arabidopsis , Arabidopsis/metabolismo , Triticum/genética , Triticum/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Resistencia a la Sequía , Estrés Fisiológico/genética , Plantas Modificadas Genéticamente/genética , Tamaño de los Órganos , Estomas de Plantas/fisiología , Sequías , Regulación de la Expresión Génica de las Plantas
2.
PLoS One ; 18(3): e0272381, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36877672

RESUMEN

OBJECTIVE: To determine the clinical manifestations, risk factors, treatment modalities and maternal outcomes in pregnant women with lab-confirmed COVID-19 and compare it with COVID-19 negative pregnant women in same age group. DESIGN: Multicentric case-control study. DATA SOURCES: Ambispective primary data collection through paper-based forms from 20 tertiary care centres across India between April and November 2020. STUDY POPULATION: All pregnant women reporting to the centres with a lab-confirmed COVID-19 positive result matched with controls. DATA QUALITY: Dedicated research officers extracted hospital records, using modified WHO Case Record Forms (CRF) and verified for completeness and accuracy. STATISTICAL ANALYSIS: Data converted to excel files and statistical analyses done using STATA 16 (StataCorp, TX, USA). Odds ratios (ORs) with 95% confidence intervals (CI) estimated using unconditional logistic regression. RESULTS: A total of 76,264 women delivered across 20 centres during the study period. Data of 3723 COVID positive pregnant women and 3744 age-matched controls was analyzed. Of the positive cases 56·9% were asymptomatic. Antenatal complications like preeclampsia and abruptio placentae were seen more among the cases. Induction and caesarean delivery rates were also higher among Covid positive women. Pre-existing maternal co-morbidities increased need for supportive care. There were 34 maternal deaths out of the 3723(0.9%) positive mothers, while covid negative deaths reported from all the centres were 449 of 72,541 (0·6%). CONCLUSION: Covid-19 infection predisposed to adverse maternal outcomes in a large cohort of Covid positive pregnant women as compared to the negative controls.


Asunto(s)
Desprendimiento Prematuro de la Placenta , COVID-19 , Embarazo , Humanos , Femenino , COVID-19/epidemiología , Estudios de Casos y Controles , India/epidemiología , Madres
3.
Mol Biol Rep ; 50(3): 2221-2229, 2023 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-36564657

RESUMEN

BACKGROUND: In-vivo maternal haploids serve as the basis of doubled haploid (DH) breeding in maize. R1-navajo (R1-nj) gene governing anthocyanin colouration in the endosperm and embryo is widely used to identify haploid seeds. However, the expression of R1-nj depends on genetic-background of source-germplasm used for deriving DH-lines. Further, presence of C1-Inhibitor (C1-I) gene suppresses the expression of R1-nj, thus makes the selection of haploids difficult. METHODS: In the present study, 178 subtropically-adapted maize inbreds were crossed with two R1-nj donors 'that do not have haploid induction genes'. Of these, 76.4% inbreds developed purple colour in endosperm, while 23.6% did not show any colouration. In case of scutellum, 62.9% inbreds possessed colour and 37.1% were colourless. The anthocyanin intensity varied greatly, with 19.66% and 42.98% inbreds displayed the least intensity, while 16.85% and 0.84% inbreds showed the highest intensity in endosperm and scutellum, respectively. Two C1-I specific breeder-friendly markers (MGU-CI-InDel8 and MGU-C1-SNP1) covering (i) 8 bp InDel and (ii) A to G SNP, respectively, were developed. MGU-CI-InDel8 and MGU-C1-SNP1 markers predicted presence of C1-I allele with 92.9% and 84.7% effectiveness, respectively. However, when both markers were considered together, they provided 100% effectiveness. CONCLUSIONS: These markers of C1-I gene would help in saving valuable resources and time during haploid induction in maize. The information generated here assume great significance in DH breeding of maize.


Asunto(s)
Antocianinas , Zea mays , Haploidia , Zea mays/genética , Antocianinas/genética , Fitomejoramiento , Pigmentación/genética
4.
Front Genet ; 13: 932166, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35983411

RESUMEN

Basmati rice is known for its extra-long slender grains, exceptional kernel dimensions after cooking, high volume expansion, and strong aroma. Developing high yielding Basmati rice varieties with good cooking quality is a gigantic task. Therefore, identifying the genomic regions governing the grain and cooked kernel dimension traits is of utmost importance for its use in marker-assisted breeding. Although several QTLs governing grain dimension traits have been reported, limited attempts have been made to map QTLs for grain and cooked kernel dimension traits of Basmati rice. In the current study, a population of recombinant inbred lines (RIL) was generated from a cross of Sonasal and Pusa Basmati 1121 (PB1121). In the RIL population, there was a significant positive correlation among the length (RRL: rough rice length, MRL: milled rice length, CKL: cooked kernel length) and breadth (RRB: rough rice breadth, MRB: milled rice breadth and CKB: cooked kernel breadth) of the related traits, while there was significant negative correlation between them. QTL mapping has led to the identification of four major genomic regions governing MRL and CKL. Two QTLs co-localize with the earlier reported major gene GS3 and a QTL qGRL7.1, while the remaining two QTLs viz., qCKL3.2 (qMRL3.2) and qCKL4.1 (qMRL4.1) were novel. The QTL qCKL3.2 has been bracketed to a genomic region of 0.78 Mb between the markers RM15247 and RM15281. Annotation of this region identified 18 gene models, of which the genes predicted to encode pentatricopeptides and brassinosteroid insensitive 1-associated receptor kinase 1 precursor may be the putative candidate genes. Furthermore, we identified a novel QTL qKER2.1 governing kernel elongation ratio (KER) in Basmati rice.

5.
Front Plant Sci ; 12: 659789, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34093617

RESUMEN

Pearl millet is a climate-resilient, nutritious crop with low input requirements that could provide economic returns in marginal agro-ecologies. In this study, we report quantitative trait loci (QTLs) for iron (Fe) and zinc (Zn) content from three distinct production environments. We generated a genetic linkage map using 210 F6 recombinant inbred line (RIL) population derived from the (PPMI 683 × PPMI 627) cross using genome-wide simple sequence repeats (SSRs). The molecular linkage map (seven linkage groups) of 151 loci was 3,273.1 cM length (Kosambi). The content of grain Fe in the RIL population ranged between 36 and 114 mg/Kg, and that of Zn from 20 to 106 mg/Kg across the 3 years (2014-2016) at over the three locations (Delhi, Dharwad, and Jodhpur). QTL analysis revealed a total of 22 QTLs for grain Fe and Zn, of which 14 were for Fe and eight were for Zn on three consecutive years at all locations. The observed phenotypic variance (R 2) explained by different QTLs for grain Fe and Zn content ranged from 2.85 (QGFe.E3.2014-2016_Q3) to 19.66% (QGFe.E1.2014-2016_Q3) and from 2.93 (QGZn.E3.2014-2016_Q3) to 25. 95% (QGZn.E1.2014-2016_Q1), respectively. Two constitutive expressing QTLs for both Fe and Zn co-mapped in this population, one on LG 2 and second one on LG 3. Inside the QTLs candidate genes such as Ferritin gene, Al3+ Transporter, K+ Transporters, Zn2+ transporters and Mg2+ transporters were identified using bioinformatics approaches. The identified QTLs and candidate genes could be useful in pearl millet population improvement programs, seed, restorer parents, and marker-assisted selection programs.

6.
Plants (Basel) ; 10(3)2021 Mar 16.
Artículo en Inglés | MEDLINE | ID: mdl-33809618

RESUMEN

Rice germplasm is a rich resource for discovering genes associated with salt tolerance. In the current study, a set of 96 accessions were evaluated for seedling stage salinity tolerance and its component traits. Significant phenotypic variation was observed among the genotypes for all the measured traits and eleven accessions with high level of salt tolerance at seedling stage were identified. The germplasm set comprised of three sub-populations and genome-wide association study (GWAS) identified a total of 23 marker-trait associations (MTAs) for traits studied. These MTAs were located on rice chromosomes 1, 2, 5, 6, 7, 9, and 12 and explained the trait phenotypic variances ranging from 13.98 to 29.88 %. Twenty-one MTAs identified in this study were located either in or near the previously reported quantitative trait loci (QTLs), while two MTAs namely, qSDW2.1 and qSNC5 were novel. A total of 18 and 13 putative annotated candidate genes were identified in a genomic region spanning ~200 kb around the MTAs qSDW2.1 and qSNC5, respectively. Some of the important genes underlying the novel MTAs were OsFBA1,OsFBL7, and mTERF which are known to be associated with salinity tolerance in crops. These MTAs pave way for combining salinity tolerance with high yield in rice genotypes through molecular breeding.

7.
Aorta (Stamford) ; 8(3): 80-82, 2020 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-33152789

RESUMEN

About one-tenth of patients with untreated chronic syphilis and tertiary syphilis develop structural complications involving the coronary ostia, ascending aorta, or aortic root. We describe a unique case of a large aortic root aneurysm of the noncoronary sinus with extrinsic compression of the right coronary artery, a complication of tertiary syphilis. Surgical intervention involved valve-sparing aortic root reconstruction with right coronary ostia reimplantation (hemi-Yacoub). The patient's postoperative course was uneventful; he is healthy approximately 2 years later.

8.
Rice (N Y) ; 13(1): 68, 2020 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-32930909

RESUMEN

BACKGROUND: Direct-seeded rice (DSR) is a potential technology for sustainable rice farming as it saves water and labor. However, higher incidence of weed under DSR limits productivity. Therefore, there is a need to develop herbicide tolerant (HT) rice varieties. RESULTS: We used marker assisted backcross breeding (MABB) to transfer a mutant allele of Acetohydroxy acid synthase (AHAS) gene, which confers tolerance to imidazolinone group of herbicides from the donor parent (DP) "Robin" into the genetic background of an elite popular Basmati rice variety, Pusa Basmati 1121 (PB 1121). Foreground selection was done using the AHAS gene linked Simple Sequence Repeat (SSR) marker RM6844 and background selection was performed using 112 genome-wide SSR markers polymorphic between PB 1121 and Robin. Phenotypic selection for agronomic, Basmati grain and cooking quality traits in each generation was carried out to improve the recovery of recurrent parent phenome (RPP). Finally, a set of 12 BC4F4 near isogenic lines (NILs), with recurrent parent genome (RPG) recovery ranging from 98.66 to 99.55% were developed and evaluated. PB 1121-HT NILs namely 1979-14-7-33-99-10, 1979-14-7-33-99-15 and 1979-14-7-33-99-66 were found superior to PB 1121 in yield with comparable grain and cooking quality traits and herbicide tolerance similar to Robin. CONCLUSION: Overall, the present study reports successful development of HT NILs in the genetic background of popular Basmati rice variety, PB 1121 by introgression of mutated AHAS allele. This is the first report on the development of HT Basmati rice. Superior NILs are being evaluated in the national Basmati trials, the release of which is likely to provide a viable option for the adoption of DSR technology in Basmati rice cultivation.

9.
Sci Rep ; 10(1): 13877, 2020 09 04.
Artículo en Inglés | MEDLINE | ID: mdl-32887905

RESUMEN

Marker assisted backcross breeding was used to transfer Saltol, a major QTL for seedling stage salinity tolerance from the donor FL478 to Pusa Basmati 1509 (PB 1509), a high yielding and early maturing Basmati rice variety. Foreground selection was carried out using three markers namely, AP3206f, RM3412b and RM10793, linked to Saltol. In addition, 105 genome-wide SSR markers polymorphic between FL478 and PB 1509 were used in background selection. Among the BC3F4 near isogenic lines (NILs) developed, recurrent parent genome recovery ranged from 96.67 to 98.57%. Multi-season evaluation identified some of the NILs showing significantly higher yield with grain and cooking quality comparable to PB 1509. All the NILs exhibited tolerance to salinity with significantly higher relative water content, membrane stability index and proline content as compared to PB 1509. The root and shoot concentration of Na+, K+ and Na+/K+ in NILs was at par with FL478 under stress conditions. The gene OsHKT1;5 located in the Saltol region showed higher expression levels under stress indicating its role in conferring salinity tolerance. Salt tolerant NILs of PB 1509 will be useful in stabilizing production in salt affected areas.

11.
J Agric Food Chem ; 67(22): 6091-6101, 2019 Jun 05.
Artículo en Inglés | MEDLINE | ID: mdl-31070027

RESUMEN

Conjugated fatty acids (CFAs) including both conjugated linoleic acids (CLAs) and conjugated linolenic acids (CLNAs) have various health promoting effects. These beneficial effects are comprised by their antioxidant, antiatherogenecity, anticarcinogenic activities, etc. Several reports indicate that CLNAs such as eleostearic acid, punicic acid, jacaric acid, and calendic acid possess anticancer properties. These CLNAs are produced and accumulated in seeds of certain commonly available plants. This review discusses their role in chemoprevention of cancer. Using in vitro as well as in vivo models of cancer, bioactivities of these CLNAs have been explored in detail. CLNAs have been shown to have potent anticancer activity as compared to the CLAs. Although the molecular basis of these effects has been summarized here, more detailed studies are needed to explore the underlying mechanisms. Further clinical trials are obligatory for assessing the safety and efficacy of CLNAs as an anticancer agent.


Asunto(s)
Ácidos Linolénicos/administración & dosificación , Neoplasias/prevención & control , Animales , Quimioprevención , Humanos , Ácidos Linoleicos Conjugados/administración & dosificación , Ácidos Linoleicos Conjugados/química , Ácidos Linolénicos/química
12.
J Obstet Gynaecol India ; 66(Suppl 1): 60-6, 2016 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-27651579

RESUMEN

PURPOSE: Maternal brought in dead are the patient who dies in the need of adequate medical care. These deaths are often not analyzed sincerely as they are not institutional deaths. Our aim is to find out actual life threatening cause of delay leading to death. METHOD: Patients brought dead to casualty were seen by the doctors on duty in Department of Obstetrics and Gynaecology,Gandhi Medical College, Bhopal round the clock. Cause of death was analyzed by verbal autopsy of attendants and referral letter from the institute. In this analytical study a complete evaluation of brought deaths from January 2011 to Decmeber 2014 was done. RESULTS: A total of 64 brought in deaths were reported in this 4 year duration. Most common cause of death was postpartum hemorrhage (54.68 %) followed by hypertension (15.62 %) and the most common cause of delay was delay in getting adequate treatment (56.25 %). CONCLUSION: The brought in dead are the indicator of the three delays in getting health care. Challenges appear to be enormous to be tackled. Timely management proves to be critical in preventing maternal death. Thus it appears that community education about pregnancy and its complications, EmOC training at FRU and strict adherence to referral protocol may help us to reduce the brought dead burden.

13.
Curr Genomics ; 17(3): 230-40, 2016 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-27252590

RESUMEN

Oils of plant origin have been predominantly used for food-based applications. Plant oils not only represent a non-polluting renewable resource but also provide a wide diversity in fatty acids (FAs) composition with diverse applications. Besides being edible, they are now increasingly being used in industrial applications such as paints, lubricants, soaps, biofuels etc. In addition, plants can be engineered to produce fatty acids which are nutritionally beneficial to human health. Thus these oils have potential to 1) substitute ever increasing demand of non -renewable petroleum sources for industrial application and 2) also spare the marine life by providing an alternative source to nutritionally and medically important long chain polyunsaturated fatty acids or 'Fish oil'. The biochemical pathways producing storage oils in plants have been extensively characterized, but the factors regulating fatty acid synthesis and controlling total oil content in oilseed crops are still poorly understood. Thus understanding of plant lipid metabolism is fundamental to its manipulation and increased production. This review on oils discusses fatty acids of nutritional and industrial importance, and approaches for achieving future designer vegetable oil for both edible and non-edible uses. The review will discuss the success and bottlenecks in efficient production of novel FAs in non-native plants using genetic engineering as a tool.

14.
Vet Med Int ; 2014: 853627, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24782941

RESUMEN

Respiratory diseases are the major disease crisis in small ruminants. A number of pathogenic microorganisms have been implicated in the development of respiratory disease but the importance of environmental factors in the initiation and progress of disease can never be overemphasized. They irritate the respiratory tree producing stress in the microenvironment causing a decline in the immune status of the small ruminants and thereby assisting bacterial, viral, and parasitic infections to break down the tissue defense barriers. Environmental pollutants cause acute or chronic reactions as they deposit on the alveolar surface which are characterized by inflammation or fibrosis and the formation of transitory or persistent tissue manifestation. Some of the effects of exposures may be immediate, whereas others may not be evident for many decades. Although the disease development can be portrayed as three sets of two-way communications (pathogen-environment, host-environment, and host-pathogen), the interactions are highly variable. Moreover, the environmental scenario is never static; new compounds are introduced daily making a precise evaluation of the disease burden almost impossible. The present review presents a detailed overview of these interactions and the ultimate effect on the respiratory health of sheep and goat.

15.
Plant J ; 77(5): 727-36, 2014 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-24387692

RESUMEN

Interspecific reproductive barriers are poorly understood, but are central to the biological species concept. The pre-zygotic barriers between red- and green-fruited species in the tomato clade of the genus Solanum provide a model to better understand these barriers in plants. Compatibility usually follows the SI x SC rule: pollen from self-compatible (SC) red-fruited species is rejected on pistils of the predominantly self-incompatible (SI) green-fruited species, but the reciprocal crosses are compatible. This suggests that the interspecific reproductive barrier may be linked to the intraspecific SI mechanism. However, pollen from the SC red-fruited species is also rejected by SC accessions of green-fruited species that lack S-RNase, a key protein expressed in pistils of SI Solanum species. Thus, multiple mechanisms may contribute to the barrier between red- and green-fruited species. We tested whether an S-RNase-dependent barrier is sufficient for rejection of pollen from red-fruited species by introducing functional S-RNase, HT-A and HT-B genes from SI species into Solanum lycopersicum (cultivated tomato). We found that expressing S-RNase in combination with either HT-A or HT-B in the pistil is sufficient to cause rejection of pollen from all four red-fruited species. Thus, redundant mechanisms must operate side by side to prevent crosses between red- and green-fruited species in the clade, underlining the complexity of interspecific pollination barriers. Our results also have implications for mating system transitions. We suggest that these transitions must occur in a specific sequence, and that the transition from SI to SC also affects interspecific compatibility.


Asunto(s)
Flores/fisiología , Autoincompatibilidad en las Plantas con Flores , Solanum lycopersicum/fisiología , Genes de Plantas , Proteínas de Plantas/metabolismo , Ribonucleasas/metabolismo
16.
Vet Med Int ; 2014: 373642, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-25610707
17.
J Exp Bot ; 64(1): 265-79, 2013 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-23166371

RESUMEN

Although self-incompatibility (SI) in plants has been studied extensively, far less is known about interspecific reproductive barriers. One interspecific barrier, known as unilateral incongruity or incompatibility (UI), occurs when species display unidirectional compatibility in interspecific crosses. In the wild tomato species Solanum pennellii, both SI and self-compatible (SC) populations express UI when crossed with domesticated tomato, offering a useful model system to dissect the molecular mechanisms involved in reproductive barriers. In this study, the timing of reproductive barrier establishment during pistil development was determined in SI and SC accessions of S. pennellii using a semi-in vivo system to track pollen-tube growth in developing styles. Both SI and UI barriers were absent in styles 5 days prior to flower opening, but were established by 2 days before flower opening, with partial barriers detected during a transition period 3-4 days before flower opening. The developmental expression dynamics of known SI factors, S-RNases and HT proteins, was also examined. The accumulation of HT-A protein coincided temporally and spatially with UI barriers in developing pistils. Proteomic analysis of stigma/styles from key developmental stages showed a switch in protein profiles from cell-division-associated proteins in immature stigma/styles to a set of proteins in mature stigma/styles that included S-RNases, HT-A protein and proteins associated with cell-wall loosening and defense responses, which could be involved in pollen-pistil interactions. Other prominent proteins in mature stigma/styles were those involved in lipid metabolism, consistent with the accumulation of lipid-rich material during pistil maturation.


Asunto(s)
Flores/crecimiento & desarrollo , Flores/metabolismo , Proteoma/metabolismo , Solanum/crecimiento & desarrollo , Solanum/metabolismo , Análisis de Varianza , Proteínas de Plantas/metabolismo , Tubo Polínico/crecimiento & desarrollo , Polinización/fisiología , Proteómica , Reproducción , Ribonucleasas/metabolismo , Autoincompatibilidad en las Plantas con Flores , Factores de Tiempo
18.
J Bacteriol ; 194(12): 3069-77, 2012 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-22493019

RESUMEN

The TonB system of gram-negative bacteria energizes the active transport of diverse nutrients through high-affinity TonB-gated outer membrane transporters using energy derived from the cytoplasmic membrane proton motive force. Cytoplasmic membrane proteins ExbB and ExbD harness the proton gradient to energize TonB, which directly contacts and transmits this energy to ligand-loaded transporters. In Escherichia coli, the periplasmic domain of ExbD appears to transition from proton motive force-independent to proton motive force-dependent interactions with TonB, catalyzing the conformational changes of TonB. A 10-residue deletion scanning analysis showed that while all regions except the extreme amino terminus of ExbD were indispensable for function, distinct roles for the amino- and carboxy-terminal regions of the ExbD periplasmic domain were evident. Like residue D25 in the ExbD transmembrane domain, periplasmic residues 42 to 61 facilitated the conformational response of ExbD to proton motive force. This region appears to be important for transmitting signals between the ExbD transmembrane domain and carboxy terminus. The carboxy terminus, encompassing periplasmic residues 62 to 141, was required for initial assembly with the periplasmic domain of TonB, a stage of interaction required for ExbD to transmit its conformational response to proton motive force to TonB. Residues 92 to 121 were important for all three interactions previously observed for formaldehyde-cross-linked ExbD: ExbD homodimers, TonB-ExbD heterodimers, and ExbD-ExbB heterodimers. The distinct requirement of this ExbD region for interaction with ExbB raised the possibility of direct interaction with the few residues of ExbB known to occupy the periplasm.


Asunto(s)
Proteínas de Escherichia coli/metabolismo , Escherichia coli/metabolismo , Proteínas de la Membrana/metabolismo , Escherichia coli/química , Proteínas de Escherichia coli/química , Proteínas de Escherichia coli/genética , Eliminación de Gen , Proteínas de la Membrana/química , Modelos Biológicos , Modelos Moleculares , Unión Proteica , Conformación Proteica , Mapeo de Interacción de Proteínas , Fuerza Protón-Motriz
19.
Sex Plant Reprod ; 24(3): 171-87, 2011 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-21076968

RESUMEN

The tomato clade within the genus Solanum has numerous advantages for mechanistic studies of reproductive isolation. Its thirteen closely related species, along with four closely allied Solanum species, provide a defined group with diverse mating systems that display complex interspecific reproductive barriers. Several kinds of pre- and postzygotic barriers have already been identified within this clade. Well-developed genetic maps, introgression lines, interspecific bridging lines, and the newly available draft genome sequence of the domesticated tomato (Solanum lycopersicum) are valuable tools for the genetic analysis of interspecific reproductive barriers. The excellent chromosome morphology of these diploid species allows detailed cytological analysis of interspecific hybrids. Transgenic methodologies, well developed in the Solanaceae, allow the functional testing of candidate reproductive barrier genes as well as live imaging of pollen rejection events through the use of fluorescently tagged proteins. Proteomic and transcriptomics approaches are also providing new insights into the molecular nature of interspecific barriers. Recent progress toward understanding reproductive isolation mechanisms using these molecular and genetic tools is assessed in this review.


Asunto(s)
Flores/fisiología , Especiación Genética , Polinización , Aislamiento Reproductivo , Solanum lycopersicum , Perfilación de la Expresión Génica , Especificidad de la Especie
20.
Plant J ; 64(3): 367-78, 2010 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-20804455

RESUMEN

Wild tomato species in Solanum Section Lycopersicon often exhibit two types of reproductive barriers: self-incompatibility (SI) and unilateral incompatibility or incongruity (UI), wherein the success of an inter-specific cross depends on the direction of the cross. UI pollen rejection often follows the 'SI × SC' rule, i.e. pistils of SI species reject the pollen of SC (self-compatible) species but not vice versa, suggesting that the SI and UI pollen rejection mechanisms may overlap. In order to address this question, pollen tube growth was measured after inter-specific crosses using wild tomato species as the female parents and pollen from cultivated tomato (Solanum lycopersicum). Two modes of UI pollen rejection, early and late, were observed, and both differed from SI pollen rejection. The structure and expression of known stylar SI genes were evaluated. We found that S-RNase expression is not required for either the early or late mode of UI pollen rejection. However, two HT family genes, HT-A and HT-B, map to a UI QTL. Surprisingly, we found that a gene previously implicated in SI, HT-B, is mutated in both SI and SC S. habrochaites accessions, and no HT-B protein could be detected. HT-A genes were detected and expressed in all species examined, and may therefore function in both SI and UI. We conclude that there are significant differences between SI and UI in the tomato clade, in that pollen tube growth differs between these two rejection systems, and some stylar SI factors, including S-RNase and HT-B, are not required for UI.


Asunto(s)
Hibridación Genética , Tubo Polínico/fisiología , Ribonucleasas/metabolismo , Solanum lycopersicum/fisiología , Secuencia de Aminoácidos , Mapeo Cromosómico , Genes de Plantas , Solanum lycopersicum/genética , Datos de Secuencia Molecular , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Tubo Polínico/crecimiento & desarrollo , Polinización , Sitios de Carácter Cuantitativo , Reproducción , Ribonucleasas/genética , Alineación de Secuencia , Homología de Secuencia de Aminoácido
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