Enhanced Disease Susceptibility 1 and Salicylic Acid Act Redundantly to Regulate Resistance Gene-Mediated Signaling

Resistance (R) protein–associated pathways are well known to participate in defense against a variety of microbial pathogens. Salicylic acid (SA) and its associated proteinaceous signaling components, including enhanced disease susceptibility 1 (EDS1), non–race-specific disease resistance 1 (NDR1), phytoalexin deficient 4 (PAD4), senescence associated gene 101 (SAG101), and EDS5, have been identified as components of resistance derived from many R proteins. Here, we show that EDS1 and SA fulfill redundant functions in defense signaling mediated by R proteins, which were thought to function independent of EDS1 and/or SA. Simultaneous mutations in EDS1 and the SA–synthesizing enzyme SID2 compromised hypersensitive response and/or resistance mediated by R proteins that contain coiled coil domains at their N-terminal ends. Furthermore, the expression of R genes and the associated defense signaling induced in response to a reduction in the level of oleic acid were also suppressed by compromising SA biosynthesis in the eds1 mutant background. The functional redundancy with SA was specific to EDS1. Results presented here redefine our understanding of the roles of EDS1 and SA in plant defense

SAG101 Forms a Ternary Complex with EDS1 and PAD4 and Is Required for Resistance Signaling against Turnip Crinkle Virus

EDS1, PAD4, and SAG101 are common regulators of plant immunity against many pathogens. EDS1 interacts with both PAD4 and SAG101 but direct interaction between PAD4 and SAG101 has not been detected, leading to the suggestion that the EDS1-PAD4 and EDS1-SAG101 complexes are distinct. We show that EDS1, PAD4, and SAG101 are present in a single complex in planta. While this complex is preferentially nuclear localized, it can be redirected to the cytoplasm in the presence of an extranuclear form of EDS1. PAD4 and SAG101 can in turn, regulate the subcellular localization of EDS1. We also show that the Arabidopsis genome encodes two functionally redundant isoforms of EDS1, either of which can form ternary complexes with PAD4 and SAG101. Simultaneous mutations in both EDS1 isoforms are essential to abrogate resistance (R) protein-mediated defense against turnip crinkle virus (TCV) as well as avrRps4 expressing Pseudomonas syringae. Interestingly, unlike its function as a PAD4 substitute in bacterial resistance, SAG101 is required for R-mediated resistance to TCV, thus implicating a role for the ternary complex in this defense response. However, only EDS1 is required for HRT-mediated HR to TCV, while only PAD4 is required for SA-dependent induction of HRT. Together, these results suggest that EDS1, PAD4 and SAG101 also perform independent functions in HRT-mediated resistance

Machine Learning Approach for Cardiovascular Risk and Coronary Artery Calcification Score

Coronary artery calcification (CAC) could assist in the discovery of new risk elements for coronary artery disorder. CAC evaluation, on the other hand, is difficult due to the wide range of CAC in the populations. As a reason, evaluating and analysing data among research have become complicated. In the Research of Inherited Risk Factors for Coronary Atherosclerosis, we used CAC information to test the effects of different analytical methodologies on the correlation with recognized cardiovascular risk elements in asymptomatic patients. Cardiac computed tomography (CT) is also seeing an increase in examinations, and machine learning (ML) could assist with the growing amount of extracted data. Furthermore, there are other sectors in cardiac CT where machine learning could be crucial, including coronary calcium scoring, perfusion, and CT angiography. The establishment of risk evaluation algorithms based on information from CAC utilizing machine learning could assist in the categorization of patients undergoing cardiovascular into distinct risk groups and effectively adapt their treatments to their unique situations. Our findings imply that for forecasting CVD occurrences in asymptomatic people, age-sex segmentation by CAC percentile rank is as effective as absolute CAC scoring. Longitudinal population-based investigations are currently underway and would offer further definitive findings. While machine learning is a strong technology with a lot of possibilities, its implementations in the domain of cardiac CAC are generally in the early stages of development and are not currently commonly accessible in medical practise because of the requirement for substantial verification. Enhanced machine learning will, however, have a significant effect on cardiovascular and coronary artery calcification in the upcoming years

Impact of macroporosity on catalytic upgrading of fast pyrolysis bio-oil by esterification over silica sulfonic acids

Fast pyrolysis bio-oils possess unfavourable physicochemical properties and poor stability, due in large part to the presence of carboxylic acids, which hinders their use as biofuels. Catalytic esterification offers an atom and energy efficient route to upgrade pyrolysis bio-oils. Propyl sulfonic acid silicas are active for carboxylic acid esterification but suffer mass-transport limitations for bulky substrates. Macropore (200 nm) incorporation enhances the activity of mesoporous SBA-15 architectures (post-functionalised by hydrothermal saline promoted grafting) for the esterification of linear carboxylic acids, with the magnitude of turnover frequency (TOF) enhancement increasing with chain length from 5 % (C3) to 110 % (C12). Macroporous-mesoporous PrSO3H/SBA-15 also offers a two-fold TOF enhancement over its mesoporous analogue for the esterification of a real thermal fast pyrolysis bio-oil derived from woodchips. The total acid number was reduced by 57 %, with GCxGC-ToFMS evidencing ester and ether formation accompanying loss of acid, phenolic, aldehyde and ketone components

An Update on the Intracellular and Intercellular Trafficking of Carmoviruses

[EN] Despite harboring the smallest genomes among plant RNA viruses, carmoviruses have emerged as an ideal model system for studying essential steps of the viral cycle including intracellular and intercellular trafficking. Two small movement proteins, formerly known as double gene block proteins (DGBp1 and DGBp2), have been involved in the movement throughout the plant of some members of carmovirus genera. DGBp1 RNA-binding capability was indispensable for cell-to-cell movement indicating that viral genomes must interact with DGBp1 to be transported. Further investigation on Melon necrotic spot virus (MNSV) DGBp1 subcellular localization and dynamics also supported this idea as this protein showed an actin-dependent movement along microfilaments and accumulated at the cellular periphery. Regarding DGBp2, subcellular localization studies showed that MNSV and Pelargonium flower break virus DGBp2s were inserted into the endoplasmic reticulum (ER) membrane but only MNSV DGBp2 trafficked to plasmodesmata (PD) via the Golgi apparatus through a COPII-dependent pathway. DGBp2 function is still unknown but its localization at PD was a requisite for an efficient cell-to-cell movement. It is also known that MNSV infection can induce a dramatic reorganization of mitochondria resulting in anomalous organelles containing viral RNAs. These putative viral factories were frequently found associated with the ER near the PD leading to the possibility that MNSV movement and replication could be spatially linked. Here, we update the current knowledge of the plant endomembrane system involvement in carmovirus intra-and intercellular movement and the tentative model proposed for MNSV transport within plant cells.This work was funded by grant BIO2014-54862-R from the Spanish Direccion General de Investigacion Cientifica y Tecnica (DGICYT) and the Prometeo Program GV2014/010 from the Generalitat Valenciana.Navarro Bohigues, JA.; Pallás Benet, V. (2017). An Update on the Intracellular and Intercellular Trafficking of Carmoviruses. Frontiers in Plant Science. 8:1-7. https://doi.org/10.3389/fpls.2017.01801S178Adams, M. J., Lefkowitz, E. J., King, A. M. Q., Harrach, B., Harrison, R. L., Knowles, N. J., … Davison, A. J. (2016). Ratification vote on taxonomic proposals to the International Committee on Taxonomy of Viruses (2016). Archives of Virology, 161(10), 2921-2949. doi:10.1007/s00705-016-2977-6Blake, J. A., Lee, K. W., Morris, T. J., & Elthon, T. E. (2007). Effects of turnip crinkle virus infection on the structure and function of mitochondria and expression of stress proteins in turnips. Physiologia Plantarum, 129(4), 698-706. doi:10.1111/j.1399-3054.2006.00852.xBlanco-Pérez, M., Pérez-Cañamás, M., Ruiz, L., & Hernández, C. (2016). Efficient Translation of Pelargonium line pattern virus RNAs Relies on a TED-Like 3´-Translational Enhancer that Communicates with the Corresponding 5´-Region through a Long-Distance RNA-RNA Interaction. PLOS ONE, 11(4), e0152593. doi:10.1371/journal.pone.0152593Brandizzi, F., Frangne, N., Marc-Martin, S., Hawes, C., Neuhaus, J.-M., & Paris, N. (2002). The Destination for Single-Pass Membrane Proteins Is Influenced Markedly by the Length of the Hydrophobic Domain. The Plant Cell, 14(5), 1077-1092. doi:10.1105/tpc.000620Carrington, J. C., Heaton, L. A., Zuidema, D., Hillman, B. I., & Morris, T. J. (1989). The genome structure of turnip crinkle virus. Virology, 170(1), 219-226. doi:10.1016/0042-6822(89)90369-3Chandra-Shekara, A. C., Navarre, D., Kachroo, A., Kang, H.-G., Klessig, D., & Kachroo, P. (2004). Signaling requirements and role of salicylic acid in HRT- and rrt-mediated resistance to turnip crinkle virus in Arabidopsis. The Plant Journal, 40(5), 647-659. doi:10.1111/j.1365-313x.2004.02241.xCohen, Y., Gisel, A., & Zambryski, P. C. (2000). Cell-to-Cell and Systemic Movement of Recombinant Green Fluorescent Protein-Tagged Turnip Crinkle Viruses. Virology, 273(2), 258-266. doi:10.1006/viro.2000.0441Cohen, Y., Qu, F., Gisel, A., Morris, T. J., & Zambryski, P. C. (2000). Nuclear Localization of Turnip Crinkle Virus Movement Protein p8. Virology, 273(2), 276-285. doi:10.1006/viro.2000.0440Gao, F., Kasprzak, W., Stupina, V. A., Shapiro, B. A., & Simon, A. E. (2012). A Ribosome-Binding, 3′ Translational Enhancer Has a T-Shaped Structure and Engages in a Long-Distance RNA-RNA Interaction. Journal of Virology, 86(18), 9828-9842. doi:10.1128/jvi.00677-12García-Castillo, S., Sánchez-Pina, M. A., & Pallás, V. (2003). Spatio-temporal analysis of the RNAs, coat and movement (p7) proteins of Carnation mottle virus in Chenopodium quinoa plants. Journal of General Virology, 84(3), 745-749. doi:10.1099/vir.0.18715-0Genovés, A., Navarro, J. A., & Pallás, V. (2006). Functional analysis of the five melon necrotic spot virus genome-encoded proteins. Journal of General Virology, 87(8), 2371-2380. doi:10.1099/vir.0.81793-0Genovés, A., Navarro, J. A., & Pallás, V. (2009). A self-interacting carmovirus movement protein plays a role in binding of viral RNA during the cell-to-cell movement and shows an actin cytoskeleton dependent location in cell periphery. Virology, 395(1), 133-142. doi:10.1016/j.virol.2009.08.042Genoves, A., Pallas, V., & Navarro, J. A. (2011). 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Virology, 395(2), 232-242. doi:10.1016/j.virol.2009.09.022Kawakami, S., Watanabe, Y., & Beachy, R. N. (2004). Tobacco mosaic virus infection spreads cell to cell as intact replication complexes. Proceedings of the National Academy of Sciences, 101(16), 6291-6296. doi:10.1073/pnas.0401221101Krczal, G. (1995). Transmission of Pelargonium Flower Break Virus (PFBV) in Irrigation Systems and by Thrips. Plant Disease, 79(2), 163. doi:10.1094/pd-79-0163Lerch-Bader, M., Lundin, C., Kim, H., Nilsson, I., & von Heijne, G. (2008). Contribution of positively charged flanking residues to the insertion of transmembrane helices into the endoplasmic reticulum. Proceedings of the National Academy of Sciences, 105(11), 4127-4132. doi:10.1073/pnas.0711580105Lesemann, D.-E., & Adam, G. (1994). ELECTRON MICROSCOPICAL AND SEROLOGICAL STUDIES ON FOUR ISOMETRICAL PELARGONIUM VIRUSES. Acta Horticulturae, (377), 41-54. doi:10.17660/actahortic.1994.377.3Li, W., Qu, F., & Morris, T. J. (1998). Cell-to-Cell Movement of Turnip Crinkle Virus Is Controlled by Two Small Open Reading Frames That Functionin trans. Virology, 244(2), 405-416. doi:10.1006/viro.1998.9125Liu, C., & Nelson, R. S. (2013). The cell biology of Tobacco mosaic virus replication and movement. Frontiers in Plant Science, 4. doi:10.3389/fpls.2013.00012Marcos, J. F., Vilar, M., Pérez-Payá, E., & Pallás, V. (1999). In VivoDetection, RNA-Binding Properties and Characterization of the RNA-Binding Domain of the p7 Putative Movement Protein from Carnation Mottle Carmovirus (CarMV). Virology, 255(2), 354-365. doi:10.1006/viro.1998.9596Martínez-Gil, L., Johnson, A. E., & Mingarro, I. (2010). Membrane Insertion and Biogenesis of the Turnip Crinkle Virus p9 Movement Protein. Journal of Virology, 84(11), 5520-5527. doi:10.1128/jvi.00125-10Martínez-Gil, L., Saurí, A., Vilar, M., Pallás, V., & Mingarro, I. (2007). Membrane insertion and topology of the p7B movement protein of Melon Necrotic Spot Virus (MNSV). Virology, 367(2), 348-357. doi:10.1016/j.virol.2007.06.006Martínez-Turiño, S., & Hernández, C. (2009). Inhibition of RNA silencing by the coat protein of Pelargonium flower break virus: distinctions from closely related suppressors. Journal of General Virology, 90(2), 519-525. doi:10.1099/vir.0.006098-0Martínez-Turiño, S., & Hernández, C. (2011). A membrane-associated movement protein of Pelargonium flower break virus shows RNA-binding activity and contains a biologically relevant leucine zipper-like motif. Virology, 413(2), 310-319. doi:10.1016/j.virol.2011.03.001Martínez-Turiño, S., & Hernández, C. (2012). Analysis of the subcellular targeting of the smaller replicase protein of Pelargonium flower break virus. Virus Research, 163(2), 580-591. doi:10.1016/j.virusres.2011.12.011Mello, A. F. S., Clark, A. J., & Perry, K. L. (2009). Capsid protein of cowpea chlorotic mottle virus is a determinant for vector transmission by a beetle. Journal of General Virology, 91(2), 545-551. doi:10.1099/vir.0.016402-0Miras, M., Sempere, R. N., Kraft, J. J., Miller, W. A., Aranda, M. A., & Truniger, V. (2013). Interfamilial recombination between viruses led to acquisition of a novel translation-enhancing RNA element that allows resistance breaking. New Phytologist, 202(1), 233-246. doi:10.1111/nph.12650Mochizuki, T., Hirai, K., Kanda, A., Ohnishi, J., Ohki, T., & Tsuda, S. (2009). Induction of necrosis via mitochondrial targeting of Melon necrotic spot virus replication protein p29 by its second transmembrane domain. Virology, 390(2), 239-249. doi:10.1016/j.virol.2009.05.012Morozov, S. Y., & Solovyev, A. G. (2003). Triple gene block: modular design of a multifunctional machine for plant virus movement. Journal of General Virology, 84(6), 1351-1366. doi:10.1099/vir.0.18922-0Mueller, S. J., & Reski, R. (2015). Mitochondrial Dynamics and the ER: The Plant Perspective. Frontiers in Cell and Developmental Biology, 3. doi:10.3389/fcell.2015.00078Navarro, J. A., Genovés, A., Climent, J., Saurí, A., Martínez-Gil, L., Mingarro, I., & Pallás, V. (2006). RNA-binding properties and membrane insertion of Melon necrotic spot virus (MNSV) double gene block movement proteins. Virology, 356(1-2), 57-67. doi:10.1016/j.virol.2006.07.040Nieto, C., Morales, M., Orjeda, G., Clepet, C., Monfort, A., Sturbois, B., … Bendahmane, A. (2006). AneIF4Eallele confers resistance to an uncapped and non-polyadenylated RNA virus in melon. The Plant Journal, 48(3), 452-462. doi:10.1111/j.1365-313x.2006.02885.xOhki, T., Akita, F., Mochizuki, T., Kanda, A., Sasaya, T., & Tsuda, S. (2010). The protruding domain of the coat protein of Melon necrotic spot virus is involved in compatibility with and transmission by the fungal vector Olpidium bornovanus. Virology, 402(1), 129-134. doi:10.1016/j.virol.2010.03.020Panavas, T., Hawkins, C. M., Panaviene, Z., & Nagy, P. D. (2005). The role of the p33:p33/p92 interaction domain in RNA replication and intracellular localization of p33 and p92 proteins of Cucumber necrosis tombusvirus. Virology, 338(1), 81-95. doi:10.1016/j.virol.2005.04.025Powers, J. G., Sit, T. L., Qu, F., Morris, T. J., Kim, K.-H., & Lommel, S. A. (2008). A Versatile Assay for the Identification of RNA Silencing Suppressors Based on Complementation of Viral Movement. Molecular Plant-Microbe Interactions®, 21(7), 879-890. doi:10.1094/mpmi-21-7-0879Qu, F., Ren, T., & Morris, T. J. (2003). The Coat Protein of Turnip Crinkle Virus Suppresses Posttranscriptional Gene Silencing at an Early Initiation Step. Journal of Virology, 77(1), 511-522. doi:10.1128/jvi.77.1.511-522.2003Riviere, C. J., & Rochon, D. M. (1990). Nucleotide sequence and genomic organization of melon necrotic spot virus. Journal of General Virology, 71(9), 1887-1896. doi:10.1099/0022-1317-71-9-1887Romero-Brey, I., & Bartenschlager, R. (2014). 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A model for transport of a viral membrane protein through the early secretory pathway: minimal sequence and endoplasmic reticulum lateral mobility requirements. The Plant Journal, 77(6), 863-879. doi:10.1111/tpj.12435Shi, Y., Ryabov, E. V., van Wezel, R., Li, C., Jin, M., Wang, W., … Hong, Y. (2009). Suppression of local RNA silencing is not sufficient to promote cell-to-cell movement ofTurnip crinkle virusinNicotiana benthamiana. Plant Signaling & Behavior, 4(1), 15-22. doi:10.4161/psb.4.1.7573Teakle, D. S. (1980). FUNGI. Vectors of Plant Pathogens, 417-438. doi:10.1016/b978-0-12-326450-3.50021-8Thomas, C. L., Leh, V., Lederer, C., & Maule, A. J. (2003). Turnip crinkle virus coat protein mediates suppression of RNA silencing in nicotiana benthamiana. Virology, 306(1), 33-41. doi:10.1016/s0042-6822(02)00018-1Tilsner, J., Linnik, O., Louveaux, M., Roberts, I. M., Chapman, S. N., & Oparka, K. J. (2013). 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Defence Responses of Arabidopsis thaliana to Infection by Pseudomonas syringae Are Regulated by the Circadian Clock

The circadian clock allows plants to anticipate predictable daily changes in abiotic stimuli, such as light; however, whether the clock similarly allows plants to anticipate interactions with other organisms is unknown. Here we show that Arabidopsis thaliana (Arabidopsis) has circadian clock-mediated variation in resistance to the virulent bacterial pathogen Pseudomonas syringae pv. tomato DC3000 (Pst DC3000), with plants being least susceptible to infection in the subjective morning. We suggest that the increased resistance to Pst DC3000 observed in the morning in Col-0 plants results from clock-mediated modulation of pathogen associated molecular pattern (PAMP)-triggered immunity. Analysis of publicly available microarray data revealed that a large number of Arabidopsis defence-related genes showed both diurnal- and circadian-regulation, including genes involved in the perception of the PAMP flagellin which exhibit a peak in expression in the morning. Accordingly, we observed that PAMP-triggered callose deposition was significantly higher in wild-type plants inoculated with Pst DC3000 hrpA in the subjective morning than in the evening, while no such temporal difference was evident in arrhythmic plants. Our results suggest that PAMP-triggered immune responses are modulated by the circadian clock and that temporal regulation allows plants to anticipate and respond more effectively to pathogen challenges in the daytime

Allele-Specific Virulence Attenuation of the Pseudomonas syringae HopZ1a Type III Effector via the Arabidopsis ZAR1 Resistance Protein

Plant resistance (R) proteins provide a robust surveillance system to defend against potential pathogens. Despite their importance in plant innate immunity, relatively few of the ∼170 R proteins in Arabidopsis have well-characterized resistance specificity. In order to identify the R protein responsible for recognition of the Pseudomonas syringae type III secreted effector (T3SE) HopZ1a, we assembled an Arabidopsis R gene T–DNA Insertion Collection (ARTIC) from publicly available Arabidopsis thaliana insertion lines and screened it for plants lacking HopZ1a-induced immunity. This reverse genetic screen revealed that the Arabidopsis R protein HOPZ-ACTIVATED RESISTANCE 1 (ZAR1; At3g50950) is required for recognition of HopZ1a in Arabidopsis. ZAR1 belongs to the coiled-coil (CC) class of nucleotide binding site and leucine-rich repeat (NBS–LRR) containing R proteins; however, the ZAR1 CC domain phylogenetically clusters in a clade distinct from other related Arabidopsis R proteins. ZAR1–mediated immunity is independent of several genes required by other R protein signaling pathways, including NDR1 and RAR1, suggesting that ZAR1 possesses distinct signaling requirements. The closely-related T3SE protein, HopZ1b, is still recognized by zar1 Arabidopsis plants indicating that Arabidopsis has evolved at least two independent R proteins to recognize the HopZ T3SE family. Also, in Arabidopsis zar1 plants HopZ1a promotes P. syringae growth indicative of an ancestral virulence function for this T3SE prior to the evolution of recognition by the host resistance protein ZAR1. Our results demonstrate that the Arabidopsis resistance protein ZAR1 confers allele-specific recognition and virulence attenuation of the Pseudomonas syringae T3SE protein HopZ1a

The Cysteine Rich Necrotrophic Effector SnTox1 Produced by Stagonospora nodorum Triggers Susceptibility of Wheat Lines Harboring Snn1

The wheat pathogen Stagonospora nodorum produces multiple necrotrophic effectors (also called host-selective toxins) that promote disease by interacting with corresponding host sensitivity gene products. SnTox1 was the first necrotrophic effector identified in S. nodorum, and was shown to induce necrosis on wheat lines carrying Snn1. Here, we report the molecular cloning and validation of SnTox1 as well as the preliminary characterization of the mechanism underlying the SnTox1-Snn1 interaction which leads to susceptibility. SnTox1 was identified using bioinformatics tools and verified by heterologous expression in Pichia pastoris. SnTox1 encodes a 117 amino acid protein with the first 17 amino acids predicted as a signal peptide, and strikingly, the mature protein contains 16 cysteine residues, a common feature for some avirulence effectors. The transformation of SnTox1 into an avirulent S. nodorum isolate was sufficient to make the strain pathogenic. Additionally, the deletion of SnTox1 in virulent isolates rendered the SnTox1 mutated strains avirulent on the Snn1 differential wheat line. SnTox1 was present in 85% of a global collection of S. nodorum isolates. We identified a total of 11 protein isoforms and found evidence for strong diversifying selection operating on SnTox1. The SnTox1-Snn1 interaction results in an oxidative burst, DNA laddering, and pathogenesis related (PR) gene expression, all hallmarks of a defense response. In the absence of light, the development of SnTox1-induced necrosis and disease symptoms were completely blocked. By comparing the infection processes of a GFP-tagged avirulent isolate and the same isolate transformed with SnTox1, we conclude that SnTox1 may play a critical role during fungal penetration. This research further demonstrates that necrotrophic fungal pathogens utilize small effector proteins to exploit plant resistance pathways for their colonization, which provides important insights into the molecular basis of the wheat-S. nodorum interaction, an emerging model for necrotrophic pathosystems

Towards molecular breeding of reproductive traits in cereal crops

The transition from vegetative to reproductive phase, flowering per se, floral organ development, panicle structure and morphology, meiosis, pollination and fertilization, cytoplasmic male sterility (CMS) and fertility restoration, and grain development are the main reproductive traits. Unlocking their genetic insights will enable plant breeders to manipulate these traits in cereal germplasm enhancement. Multiple genes or quantitative trait loci (QTLs) affecting flowering (phase transition, photoperiod and vernalization, flowering per se), panicle morphology and grain development have been cloned, and gene expression research has provided new information about the nature of complex genetic networks involved in the expression of these traits. Molecular biology is also facilitating the identification of diverse CMS sources in hybrid breeding. Few Rf (fertility restorer) genes have been cloned in maize, rice and sorghum. DNA markers are now used to assess the genetic purity of hybrids and their parental lines, and to pyramid Rf or tms (thermosensitive male sterility) genes in rice. Transgene(s) can be used to create de novo CMS trait in cereals. The understanding of reproductive biology facilitated by functional genomics will allow a better manipulation of genes by crop breeders and their potential use across species through genetic transformation