The Rice Pentatricopeptide Repeat Protein PPR756 Is Involved in Pollen Development by Affecting Multiple RNA Editing in Mitochondria.

In land plants, the pentatricopeptide repeat (PPR) proteins form a large family involved in post-transcriptional processing of RNA in mitochondria and chloroplasts, which is critical for plant development and evolutionary adaption. Although studies showed a number of PPR proteins generally influence the editing of organellar genes, few of them were characterized in detail in rice. Here, we report a PLS-E subclass PPR protein in rice, PPR756, loss of function of which led to the abolishment of RNA editing events among three mitochondrial genes includin

The mitochondrial gene orfH79 plays a critical role in impairing both male gametophyte development and root growth in CMS-Honglian rice

<p>Abstract</p> <p>Background</p> <p>Cytoplasmic male sterility (CMS) has often been associated with abnormal mitochondrial open reading frames. The mitochondrial gene <it>orfH79 </it>is a candidate gene for causing the CMS trait in CMS-Honglian (CMS-HL) rice. However, whether the <it>orfH79 </it>expression can actually induce CMS in rice remains unclear.</p> <p>Results</p> <p>Western blot analysis revealed that the ORFH79 protein is mainly present in mitochondria of CMS-HL rice and is absent in the fertile line. To investigate the function of ORFH79 protein in mitochondria, this gene was fused to a mitochondrial transit peptide sequence and used to transform wild type rice, where its expression induced the gametophytic male sterile phenotype. In addition, excessive accumulation of reactive oxygen species (ROS) in the microspore, a reduced ATP/ADP ratio, decreased mitochondrial membrane potential and a lower respiration rate in the transgenic plants were found to be similar to those in CMS-HL rice. Moreover, retarded growth of primary and lateral roots accompanied by abnormal accumulation of ROS in the root tip was observed in both transgenic rice and CMS-HL rice (YTA).</p> <p>Conclusion</p> <p>These results suggest that the expression of <it>orfH79 </it>in mitochondria impairs mitochondrial function, which affects the development of both male gametophytes and the roots of CMS-HL rice.</p

نقش بمبزين در سيری پيش از جذب

پس از صرف غذا و پيش از آنکه مواد غذايی هضم و جذب شوند، دريافت غذا بسرعت وقفه می يابد و انسان احساس سيری می کند. اين موضوع نشان می دهد که اطلاعات مربوط به اعصاب حسی يا مواد هورمونی مترشحه از بخش های فوقانی لوله گوارش موجب سيری پيش از جذب می شود. بعضي نوروترانسميترها و مواد هورمونی به عنوان عوامل فرضی سيری شناخته شده اند که يکی از آنها بمبزين است. بمبزين اعمال يک نوروترانسميتر را در تشکيلات عصبی لوله گوارش پستانداران Bombesin تقليد می کند. بمبزين به کار رفته در بطن های جانبی مغز با فعال کردن سوبستراهای عصبی پاراونتريکولار موجب وقفه دريافت غذا و هيپوانسولينمی می گردد. با تزريق داخل صفاتی بمبزين نه تنها ميزان دريافت غذا کاهش (Gastrin Releasing) GBP می يابد بلکه فاصله بين غذا نيز افزايش می يابد. بعلاوه بمبزين و سبب آزاد شدن هورمونهايی در روده می شوند که اين مواد خود بعنوان عوامل بروز سيری Peptide عمل می کنن

Development of Elite BPH-Resistant Wide-Spectrum Restorer Lines for Three and Two Line Hybrid Rice

Hybrid rice has contributed significantly to the world food security. Breeding of elite high-yield, strong-resistant broad-spectrum restorer line is an important strategy for hybrid rice in commercial breeding programs. Here, we developed three elite brown planthopper (BPH)-resistant wide-spectrum restorer lines by pyramiding big-panicle gene Gn8.1, BPH-resistant genes Bph6 and Bph9, fertility restorer genes Rf3, Rf4, Rf5, and Rf6 through molecular marker assisted selection. Resistance analysis revealed that the newly developed restorer lines showed stronger BPH-resistance than any of the single-gene donor parent Luoyang-6 and Luoyang-9. Moreover, the three new restorer lines had broad spectrum recovery capabilities for Honglian CMS, Wild abortive CMS and two-line GMS sterile lines, and higher grain yields than that of the recurrent parent 9,311 under nature field conditions. Importantly, the hybrid crosses also showed good performance for grain yield and BPH-resistance. Thus, the development of elite BPH-resistant wide-spectrum restorer lines has a promising future for breeding of broad spectrum BPH-resistant high-yield varieties

Comparative Transcriptomes Profiling of Photoperiod-sensitive Male Sterile Rice Nongken 58S During the Male Sterility Transition between Short-day and Long-day

<p>Abstract</p> <p>Background</p> <p>Photoperiod-sensitive genic male sterile (PGMS) rice, Nongken 58S, was discovered in 1973. It has been widely used for the production of hybrid rice, and great achievements have been made in improving rice yields. However, the mechanism of the male sterility transition in PGMS rice remains to be determined.</p> <p>Results</p> <p>To investigate the transcriptome during the male sterility transition in PGMS rice, the transcriptome of Nongken 58S under short-day (SD) and long-day (LD) at the glume primordium differentiation and pistil/stamen primordium forming stages was compared. Seventy-three and 128 differentially expressed genes (DEGs) were identified at the glume primordium differentiation and pistil/stamen primordium forming stages, respectively. Five and 22 genes were markedly up-regulated (≥ 5-fold), and two and five genes were considerably down-regulated (≥ 5-fold) under SD during the male sterility transition. Gene ontology annotation and pathway analysis revealed that four biological processes and the circadian rhythms and the flowering pathways coordinately regulated the male sterility transition. Further quantitative PCR analysis demonstrated that the circadian rhythms of <it>OsPRR1, OsPRR37, OsGI, Hd1, OsLHY </it>and <it>OsDof </it>in leaves were obviously different between Nongken 58S and Nongken 58 under LD conditions. Moreover, both <it>OsPRR37 </it>and <it>Hd1 </it>in the inflorescence displayed differences between Nongken 58S and Nongken 58 under both LD and SD conditions.</p> <p>Conclusion</p> <p>The results presented here indicate that the transcriptome in Nongken 58S was significantly suppressed under LD conditions. Among these DEGs, the circadian rhythm and the flowering pathway were involved in the male sterility transition. Furthermore, these pathways were coordinately involved in the male sterility transition in PGMS rice.</p

Leaves of the <i>LMX</i> transgenic rice plants demonstrate insect resistance.

<p><b>A</b>. Damage caused by rice leaf folder on the leaves of <i>LMX</i> transgenic rice plants. <b>B</b>. Ratio of the damaged leaf area to the whole leaf. <b>C</b>. Whole transgenic rice plants expressing LMX demonstrated improved resistance to rice leaf roller. Wild type plants and empty vector transgenic plants (rbcS plants) were used as the controls and homozygous LMX transgenic rice plants were used as the experimental group. Day 1 of 3^rd instar rice leaf roller larvae were utilized in the bioassay. Leaves were photographed and measured after 72 h incubation with the rice leaf folder. Plants were photographed and measured after 7 days of incubation with the rice leaf folder larvae. Values are mean ± SD, *** denotes 0.001 significance value.</p