Ca2+ sensor-mediated ROS scavenging suppresses rice immunity and is exploited by a fungal effector.

Plant immunity is activated upon pathogen perception and often affects growth and yield when it is constitutively active. How plants fine-tune immune homeostasis in their natural habitats remains elusive. Here, we discover a conserved immune suppression network in cereals that orchestrates immune homeostasis, centering on a Ca2+-sensor, RESISTANCE OF RICE TO DISEASES1 (ROD1). ROD1 promotes reactive oxygen species (ROS) scavenging by stimulating catalase activity, and its protein stability is regulated by ubiquitination. ROD1 disruption confers resistance to multiple pathogens, whereas a natural ROD1 allele prevalent in indica rice with agroecology-specific distribution enhances resistance without yield penalty. The fungal effector AvrPiz-t structurally mimics ROD1 and activates the same ROS-scavenging cascade to suppress host immunity and promote virulence. We thus reveal a molecular framework adopted by both host and pathogen that integrates Ca2+ sensing and ROS homeostasis to suppress plant immunity, suggesting a principle for breeding disease-resistant, high-yield crops.

PE-STOP: A versatile tool for installing nonsense substitutions amenable for precise reversion.

The rapid advances in genome editing technologies have revolutionized the study of gene functions in cell or animal models. The recent generation of double-stranded DNA cleavage-independent base editors has been suitably adapted for interrogation of protein-coding genes on the basis of introducing premature stop codons or disabling the start codons. However, such versions of stop/start codon-oriented genetic tools still present limitations on their versatility, base-level precision, and target specificity. Here, we exploit a newly developed prime editor (PE) that differs from base editors by its adoption of a reverse transcriptase activity, which enables incorporation of various types of precise edits templated by a specialized prime editing guide RNA. Based on such a versatile platform, we established a prime editing-empowered method (PE-STOP) for installation of nonsense substitutions, providing a complementary approach to the present gene-targeting tools. PE-STOP is bioinformatically predicted to feature substantially expanded coverage in the genome space. In practice, PE-STOP introduces stop codons with good efficiencies in human embryonic kidney 293T and N2a cells (with medians of 29% [ten sites] and 25% [four sites] editing efficiencies, respectively), while exhibiting minimal off-target effects and high on-target precision. Furthermore, given the fact that PE installs prime editing guide RNA-templated mutations, we introduce a unique strategy for precise genetic rescue of PE-STOP-dependent nonsense mutation via the same PE platform. Altogether, the present work demonstrates a versatile and specific tool for gene inactivation and for functional interrogation of nonsense mutations.

Single-nucleus transcriptome inventory of giant panda reveals cellular basis for fitness optimization under low metabolism.

BACKGROUND: Energy homeostasis is essential for the adaptation of animals to their environment and some wild animals keep low metabolism adaptive to their low-nutrient dietary supply. Giant panda is such a typical low-metabolic mammal exhibiting species specialization of extremely low daily energy expenditure. It has low levels of basal metabolic rate, thyroid hormone, and physical activities, whereas the cellular bases of its low metabolic adaptation remain rarely explored. RESULTS: In this study, we generate a single-nucleus transcriptome atlas of 21 organs/tissues from a female giant panda. We focused on the central metabolic organ (liver) and dissected cellular metabolic status by cross-species comparison. Adaptive expression mode (i.e., AMPK related) was prominently displayed in the hepatocyte of giant panda. In the highest energy-consuming organ, the heart, we found a possibly optimized utilization of fatty acid. Detailed cell subtype annotation of endothelial cells showed the uterine-specific deficiency of blood vascular subclasses, indicating a potential adaptation for a low reproductive energy expenditure. CONCLUSIONS: Our findings shed light on the possible cellular basis and transcriptomic regulatory clues for the low metabolism in giant pandas and helped to understand physiological adaptation response to nutrient stress.

A Processible and Ultrahigh-temperature Organic Photothermal Material through Spontaneous and Quantitative [2+2] Cycloaddition-Cycloreversion.

Energy conversion, particularly light to heat conversion, has garnered significant attention owing to its prospect in renewable energy exploitation and utilization. Most previous efforts have focused on developing organic photothermal materials for low-temperature applications, whereas the importance of simplifying the preparation methods of photothermal materials and enhancing their maximum photothermal temperature have been less taken. Herein, we prepare an organic near-infrared (NIR) photothermal material namely ATT by a spontaneous [2+2] cycloaddition-cycloreversion reaction. In addition to the solution-based method, ATT could also be readily preapred by ball milling in a high yield of 90% in just 15 min. ATT powder exhibits a broad absorption extending beyond 2000 nm, excellent processability, and thermal stability. Remarkably, ATT powder can reach an unprecedently temperature as high as 450 °C while maintaining excellent photostability upon photoirradiation. Leveraging its extraordinary photothermal and processable properties, ATT was used in the high-temperature applications, such as photo-ignition, photo-controlled metal processing and high-temperature shape memory, all of which offer spatiotemporal control capabilities. This work provides a new approach to prepare organic photothermal materials with high temperatures, and pave the way for their applications in extreme environments.

GS6.1 controls kernel size and plant architecture in rice.

MAIN CONCLUSION: A novel QTL GS6.1 increases yield per plant by controlling kernel size, plant architecture, and kernel filling in rice. Kernel size and plant architecture are critical agronomic traits that greatly influence kernel yield in rice. Using the single-segment substitution lines (SSSLs) with an indica cultivar Huajingxian74 as a recipient parent and American Jasmine as a donor parent, we identified a novel quantitative trait locus (QTL), named GS6.1. Near isogenic line-GS6.1 (NIL-GS6.1) produces long and narrow kernels by regulating cell length and width in the spikelet hulls, thus increasing the 1000-kernel weight. Compared with the control, the plant height, panicles per plant, panicle length, kernels per plant, secondary branches per panicle, and yield per plant of NIL-GS6.1 are increased. In addition, GS6.1 regulates the kernel filling rate. GS6.1 controls kernel size by modulating the transcription levels of part of EXPANSINs, kernel filling-related genes, and kernel size-related genes. These results indicate that GS6.1 might be beneficial for improving kernel yield and plant architecture in rice breeding by molecular design.

qGLF5 from Oryza rufipogon Griff. improves kernel shape, plant architecture, and yield in rice.

KEY MESSAGE: A novel QTL qGLF5 from Oryza rufipogon Griff. improves yield per plant and plant architecture in rice. Kernel size and plant architecture are critical agronomic traits that are key targets for improving crop yield. From the single-segment substitution lines of Oryza rufipogon Griff. in the indica cultivar Huajingxian74 (HJX74) background, we identified a novel quantitative trait locus (QTL), named qGLF5, which improves kernel shape, plant architecture, and yield per plant in rice. Compared with the control HJX74, the plant height, panicles per plant, panicle length, primary branches per panicle, secondary branches per panicle, and kernels per plant of the near-isogenic line-qGLF5 (NIL-qGLF5) are significantly increased. NIL-qGLF5 has long and narrow kernels by regulating cell number, cell length and width in the spikelet hulls. Yield per plant of NIL-qGLF5 is increased by 35.02% compared with that of HJX74. In addition, qGLF5 significantly improves yield per plant and plant architecture of NIL-gw5 and NIL-GW7. These results indicate that qGLF5 might be beneficial for improving plant architecture and kernel yield in rice breeding by molecular design.

qGL3.4 controls kernel size and plant architecture in rice.

Kernel size and plant architecture play important roles in kernel yield in rice. Cloning and functional study of genes related to kernel size and plant architecture are of great significance for breeding high-yield rice. Using the single-segment substitution lines which developed with Oryza barthii as a donor parent and an elite indica cultivar Huajingxian74 (HJX74) as a recipient parent, we identified a novel QTL (quantitative trait locus), named qGL3.4, which controls kernel size and plant architecture. Compared with HJX74, the kernel length, kernel width, 1000-kernel weight, panicle length, kernels per plant, primary branches, yield per plant, and plant height of near isogenic line-qGL3.4 (NIL-qGL3.4) are increased, whereas the panicles per plant and secondary branches per panicle of NIL-qGL3.4 are comparable to those of HJX74. qGL3.4 was narrowed to a 239.18 kb interval on chromosome 3. Cell analysis showed that NIL-qGL3.4 controlled kernel size by regulating cell growth. qGL3.4 controls kernel size at least in part through regulating the transcription levels of EXPANSINS, GS3, GL3.1, PGL1, GL7, OsSPL13 and GS5. These results indicate that qGL3.4 might be beneficial for improving kernel yield and plant architecture in rice breeding.

Rice NIN-LIKE PROTEIN 4 plays a pivotal role in nitrogen use efficiency.

Nitrogen (N) is one of the key essential macronutrients that affects rice growth and yield. Inorganic N fertilizers are excessively used to boost yield and generate serious collateral environmental pollution. Therefore, improving crop N use efficiency (NUE) is highly desirable and has been a major endeavour in crop improvement. However, only a few regulators have been identified that can be used to improve NUE in rice to date. Here we show that the rice NIN-like protein 4 (OsNLP4) significantly improves the rice NUE and yield. Field trials consistently showed that loss-of-OsNLP4 dramatically reduced yield and NUE compared with wild type under different N regimes. In contrast, the OsNLP4 overexpression lines remarkably increased yield by 30% and NUE by 47% under moderate N level compared with wild type. Transcriptomic analyses revealed that OsNLP4 orchestrates the expression of a majority of known N uptake, assimilation and signalling genes by directly binding to the nitrate-responsive cis-element in their promoters to regulate their expression. Moreover, overexpression of OsNLP4 can recover the phenotype of Arabidopsis nlp7 mutant and enhance its biomass. Our results demonstrate that OsNLP4 plays a pivotal role in rice NUE and sheds light on crop NUE improvement.

Metagenomic analysis revealed a wide distribution of antibiotic resistance genes and biosynthesis of antibiotics in the gut of giant pandas.

BACKGROUND: The gut microbiome is essential for the host's health and serves as an essential reservoir of antibiotic resistance genes (ARGs). We investigated the effects of different factors, including the dietary shifts and age, on the functional characteristics of the giant panda's gut microbiome (GPs) through shotgun metagenome sequencing. We explored the association between gut bacterial genera and ARGs within the gut based on network analysis. RESULTS: Fecal samples (n=60) from captive juvenile, adult, and geriatric GPs were processed, and variations were identified in the gut microbiome according to different ages, the abundance of novel ARGs and the biosynthesis of antibiotics. Among 667 ARGs identified, nine from the top ten ARGs had a higher abundance in juveniles. For 102 ARGs against bacteria, a co-occurrence pattern revealed a positive association for predominant ARGs with Streptococcus. A comparative KEGG pathways analysis revealed an abundant biosynthesis of antibiotics among three different groups of GPs, where it was more significantly observed in the juvenile group. A co-occurrence pattern further revealed a positive association for the top ten ARGs, biosynthesis of antibiotics, and metabolic pathways. CONCLUSION: Gut of GPs serve as a reservoir for novel ARGs and biosynthesis of antibiotics. Dietary changes and age may influence the gut microbiome's functional characteristics; however, it needs further studies to ascertain the study outcomes.

Dissection of closely linked QTLs controlling stigma exsertion rate in rice by substitution mapping.

KEY MESSAGE: Through substitution mapping strategy, two pairs of closely linked QTLs controlling stigma exsertion rate were dissected from chromosomes 2 and 3 and the four QTLs were fine mapped. Stigma exsertion rate (SER) is an important trait affecting the outcrossing ability of male sterility lines in hybrid rice. This complex trait was controlled by multiple QTLs and affected by environment condition. Here, we dissected, respectively, two pairs of tightly linked QTLs for SER on chromosomes 2 and 3 by substitution mapping. On chromosome 2, two linkage QTLs, qSER-2a and qSER-2b, were located in the region of 1288.0 kb, and were, respectively, delimited to the intervals of 234.9 kb and 214.3 kb. On chromosome 3, two QTLs, qSER-3a and qSER-3b, were detected in the region of 3575.5 kb and were narrowed down to 319.1 kb and 637.3 kb, respectively. The additive effects of four QTLs ranged from 7.9 to 9.0%. The epistatic effect produced by the interaction of qSER-2a and qSER-2b was much greater than that of qSER-3a and qSER-3b. The open reading frames were identified within the maximum intervals of qSER-2a, qSER-2b and qSER-3a, respectively. These results revealed that there are potential QTL clusters for SER in the two regions of chromosome 2 and chromosome 3. Fine mapping of the QTLs laid a foundation for cloning of the genes of SER.

GW10, a member of P450 subfamily regulates grain size and grain number in rice.

KEY MESSAGE: A quantitative trait locus GW10 is located on Chromosome 10 by map-based cloning, which encodes a P450 Subfamily protein. The GW10 regulates grain size and grain number in rice involved in the BR pathway. Grain size and grain number play extremely important roles in rice grain yield. Here, we identify GW10, which encodes a P450 subfamily protein and controls grain size and grain number by using Lemont (tropical japonica) as donor parent and HJX74 (indica) as recipient parent. The GW10 locus was mapped into a 14.6 kb region in HJX74 genomic on the long arm of chromosome 10. Lower expression of the gw10 in panicle is contributed to the shorter and narrower rice grain, and the increased number of grains per panicle. In contrast, overexpression of GW10 is contributed to longer and wider rice grain. Furthermore, the higher expression levels of some of the brassinosteroid (BR) biosynthesis and response genes are associated with the NIL-GW10. The sensitivity of the leaf angle to exogenous BR in NIL-GW10 is lower than that in NIL-gw10 and in the KO-GW10, which implied that the GW10 should involve in the brassinosteroid-mediated regulation of rice grain size and grain number.

Reverse chemical ecology: Olfactory proteins from the giant panda and their interactions with putative pheromones and bamboo volatiles.

The giant panda Ailuropoda melanoleuca belongs to the family of Ursidae; however, it is not carnivorous, feeding almost exclusively on bamboo. Being equipped with a typical carnivorous digestive apparatus, the giant panda cannot get enough energy for an active life and spends most of its time digesting food or sleeping. Feeding and mating are both regulated by odors and pheromones; therefore, a better knowledge of olfaction at the molecular level can help in designing strategies for the conservation of this species. In this context, we have identified the odorant-binding protein (OBP) repertoire of the giant panda and mapped the protein expression in nasal mucus and saliva through proteomics. Four OBPs have been identified in nasal mucus, while the other two were not detected in the samples examined. In particular, AimelOBP3 is similar to a subset of OBPs reported as pheromone carriers in the urine of rodents, saliva of the boar, and seminal fluid of the rabbit. We expressed this protein, mapped its binding specificity, and determined its crystal structure. Structural data guided the design and preparation of three protein mutants bearing single-amino acid replacements in the ligand-binding pocket, for which the corresponding binding affinity spectra were measured. We also expressed AimelOBP5, which is markedly different from AimelOBP3 and complementary in its binding spectrum. By comparing our binding data with the structures of bamboo volatiles and those of typical mammalian pheromones, we formulate hypotheses on which may be the most relevant semiochemicals for the giant panda.

An AIE-Active Conjugated Polymer with High ROS-Generation Ability and Biocompatibility for Efficient Photodynamic Therapy of Bacterial Infections.

New, biocompatible materials with favorable antibacterial activity are highly desirable. In this work, we develop a unique conjugated polymer featuring aggregation-induced emission (AIE) for reliable bacterial eradication. Thanks to the AIE and donor-π-acceptor structure, this polymer shows a high reactive oxygen species (ROS)-generation ability compared to a low-mass model compound and the common photosensitizer Chlorin E6. Moreover, the selective binding of pathogenic microorganisms over mammalian cells was found, demonstrating its biocompatibility. The effective growth inhibition of bacteria upon polymer treatment under light irradiation was validated in vitro and in vivo. Notably, the recovery from infection after treatment with our polymer is faster than that with cefalotin. Thus, this polymer holds great promise in fighting against bacteria-related infections in practical applications.

Map-based cloning of a new total loss-of-function allele of OsHMA3 causes high cadmium accumulation in rice grain.

Rice (Oryza sativa) is a major dietary source of the toxic metal cadmium (Cd). Reducing Cd transfer from soil to the rice grain is important for food safety. Rice cultivars vary widely in their Cd accumulation, but the genetic basis for this variation is not fully understood. Based on field and pot experiments comparing 26 rice cultivars, we identified a cultivar with high Cd accumulation in grain (BG367, coded as W4) and a cultivar with low grain Cd accumulation (Huajingxian 74, coded as W0). W4 showed a higher Cd translocation from roots to shoots than W0. Using chromosome single segment substitution lines derived from the two cultivars, we mapped a quantitative trait locus for Cd accumulation in grain to a 400 kb region in chromosome 7. Using yeast expression assays and transgenic complementation, we identified OsHMA3 as the causal gene at this locus. Compared with OsHMA3W0, OsHMA3W4 has a deletion of 14 amino acids predicted to be in the ATP binding domain. OsHMA3W4 showed a complete loss of transport activity for Cd in yeast assays. Taking our findings together, we have identified a new allele of OsHMA3 with a total loss-of-function, resulting in greatly elevated Cd translocation to rice shoots and grain.

Analysis of the influence of living environment and age on vaginal fungal microbiome in giant pandas (Ailuropoda melanoleuca) by high throughput sequencing.

A recent study has described the normal vaginal bacterial community in giant pandas, but there is a lack of knowledge of the fungal community residing in the vagina of giant pandas. In order to comprehensively understand the vaginal fungal microbial diversity and abundance in giant pandas, high throughput sequencing was used to analyse the ITS1 region, based on thirteen samples taken from the pandas' vaginas, which were grouped by sampling points and age. The results showed that the most abundant phyla were Basidiomycota (73.37%), followed by Ascomycota (20.04%), Zygomycota (5.23%), Glomeromycota (0.014%) and Chytridiomycota (0.006%). At the genus level, Guehomyces (37.92%) was the most abundant, followed by Cladosporium (9.072%), Trichosporon (6.2%) and Mucor (4.97%). Furthermore, Candida only accounted for a low percentage of the vaginal fungal community. With the saturation of rarefaction curves and fungal diversity indices, the samples from Dujiangyan and Chungking Safari Park (DC group) showed a higher fungal species richness and diversity than other living environments. Shannon diversity indices showed significant difference between group WL (Wolong nature reserve) and DC (P < .05). Additionally, a higher diversity was found in ten to fifteen years old (Group 2) than other groups. Group 2 and Group 3 displayed significant differences in the diversities of their vaginal fungal communities (P < .05). These data that has been collected from this research will be helpful for further study to improve the reproductive status of giant pandas.

Frequency of antimicrobial resistance and integron gene cassettes in Escherichia coli isolated from giant pandas (Ailuropoda melanoleuca) in China.

Escherichia coli (E. coli) is considered as a common opportunistic pathogen, which causes seriously intestinal infections to giant pandas (Ailuropoda melanoleuca) and other animals. The aim of this investigation was to characterize the antimicrobial resistance and integron gene cassettes in E. coli isolated from the faeces of giant pandas in China. A total of 89 E. coli were isolated, after diagnosis of isolates and genomes were extracted. All the isolates were screened for the presence of related drug-resistance genes and integron gene cassettes through the Polymerase Chain Reaction (PCR) and sequencing. In addition, antimicrobial resistance testing was performed according to the standard disk diffusion method (CLSI 2013). The results demonstrated that all the isolates were multi-drug resistance (MDR). High resistance proportions of the E. coli isolates were to streptomycin (93%), cefazolin (90%), amikacin (75%), tetracycline (65%), ampicillin (62%), cefotaxime and trimethoprim-sulfamethoxazole (54%, each). With respect to the various resistance genes; blaCTX-M, sul1, ant (3')-Ia, tetA, qnrB, tetE, floR, aac (6')-Ib, sul2, rmtA, cmlA, rmtB and tetC were identified with the respective frequencies of 44%, 45%, 38%, 37%, 35%, 27%, 26%, 20%, 18%, 15%, 10%, 7% and 4%. None of the isolates was positive for qnrA and cfr genes. Moreover, a further investigation of integron revealed that the emergence of class 1 and 2 integrons were in 47% and 8% isolates, respectively. While class 3 integron was not screened. Six types of containing in class 1 integron specific gene cassettes (dfrA12-orfF-aadA2, dfrA17-aadA5, aadA1, aadA5, dfrA1 and dfrA7) were identified. However, only one gene cassette (dfrA1-sat2-aadA1) was detected in class 2 integron. These finding emphasize that a high level of E. coli isolates harbored antibiotics resistance and integron gene cassettes, which may bring so many potential threats to the health of giant pandas.

Albino Leaf1 That Encodes the Sole Octotricopeptide Repeat Protein Is Responsible for Chloroplast Development.

Chloroplast, the photosynthetic organelle in plants, plays a crucial role in plant development and growth through manipulating the capacity of photosynthesis. However, the regulatory mechanism of chloroplast development still remains elusive. Here, we characterized a mutant with defective chloroplasts in rice (Oryza sativa), termed albino leaf1 (al1), which exhibits a distinct albino phenotype in leaves, eventually leading to al1 seedling lethality. Electronic microscopy observation demonstrated that the number of thylakoids was reduced and the structure of thylakoids was disrupted in the al1 mutant during rice development, which eventually led to the breakdown of chloroplast. Molecular cloning revealed that AL1 encodes the sole octotricopeptide repeat protein (RAP) in rice. Genetic complementation of Arabidopsis (Arabidopsis thaliana) rap mutants indicated that the AL1 protein is a functional RAP. Further analysis illustrated that three transcript variants were present in the AL1 gene, and the altered splices occurred at the 3' untranslated region of the AL1 transcript. In addition, our results also indicate that disruption of the AL1 gene results in an altered expression of chloroplast-associated genes. Consistently, proteomic analysis demonstrated that the abundance of photosynthesis-associated proteins is altered significantly, as is that of a group of metabolism-associated proteins. More specifically, we found that the loss of AL1 resulted in altered abundances of ribosomal proteins, suggesting that RAP likely also regulates the homeostasis of ribosomal proteins in rice in addition to the ribosomal RNA. Taken together, we propose that AL1, particularly the AL1a and AL1c isoforms, plays an essential role in chloroplast development in rice.

Substitution mapping of QTLs controlling seed dormancy using single segment substitution lines derived from multiple cultivated rice donors in seven cropping seasons.

KEY MESSAGE: A permanent advanced population containing 388 SSSLs was used for genetic analysis of seed dormancy; 25 QTLs including eight stable, six major and five new were identified. Seed dormancy (SD) is not only a complex biological phenomenon, but also a key practical problem in agricultural production closely related with pre-harvest sprouting (PHS). However, the genetic mechanisms of SD remain elusive. Here, we report the genetic dissection of SD in rice using 388 single segment substitution lines (SSSLs) derived from 16 donor parents. Continuous variation and positive correlations in seed germination percentages were observed in seven seasons. Genetic analysis revealed the narrow sense heritability in different seasons varied from 31.4 to 82.2% with an average value of 56.8%. In addition, 49 SSSLs exhibited significant difference to recipient parent HJX74 on SD in at least two seasons, and 12 of them were stably identified with putative QTLs in all of their corresponding cropping seasons. Based on substitution mapping, a total of 25 dormancy QTLs were detected on 11 chromosomes except the chromosome 5 with an interval length of 1.1 to 31.3 cM. The additive effects of these QTLs changed from -0.31 to -0.13, and the additive effect contributions ranged from 16.7 to 41.4%. Six QTLs, qSD3-2, qSD4-1, qSD7-1, qSD7-2, qSD7-3 and qSD11-2, showed large additive effect contributions (≥30%). Five QTLs, qSD3-3, qSD7-1, qSD7-4, qSD9-1 and qSD10-1, may represent novel ones. Furthermore, linkage and recombinant analysis delimited qSD7-1 to a locus 1.5 cM away from marker Oi2 and a 355-kb fragment flanked by RM1134 and Ui159, respectively. Taken together, this work conducts a comprehensive genetic dissection of SD and will provide more selections for breeding elite PHS-resistant rice varieties.

ER-localized adenine nucleotide transporter ER-ANT1: an integrator of energy and stress signaling in rice.

Most environmental perturbations have a direct or indirect deleterious impact on photosynthesis, and, in consequence, the overall energy status of the cell. Despite our increased understanding of convergent energy and stress signals, the connections between photosynthesis, energy and stress signals through putative common nodes are still unclear. Here we identified an endoplasmic reticulum (ER)-localized adenine nucleotide transporter1 (ER-ANT1), whose deficiency causes seedling lethality in air but viable under high CO2, exhibiting the typical photorespiratory phenotype. Metabolic analysis suggested that depletion of ER-ANT1 resulted in circadian rhythm disorders in sucrose synthesis and induced sucrose signaling pathways, indicating that the ER is involved in the regulation of vital energy metabolism in plants. In addition, the defect of ER-ANT1 triggers ER stress and activates the unfolded protein response in plant cells, suggesting ER stress and photorespiration are closely linked. These findings provide an important evidence for a key role of ER-localized ER-ANT1 in convergent energy and stress signals in rice. Our findings support the idea that ATP is a central signal involved in the plant response to a variety of stresses.

Development of a platform for breeding by design of CMS restorer lines based on an SSSL library in rice (Oryza sativa L.).

Exploitation of the heterosis of hybrid rice has shown great success in the improvement of rice yields. However, few genotypes exhibit strong restoration ability as effective restorers of cytoplasmic male sterility (CMS) in the development of hybrid rice. In this study, we developed a platform for the breeding by design of CMS restorer lines based on a library of chromosomal single segment substitution lines (SSSLs) in the Huajingxian74 (HJX74) genetic background. The target genes for breeding by design, Rf34 and Rf44, which are associated with a strong restoration ability, and gs3, gw8, Wxg1 and Alk, which are associated with good grain quality, were selected from the HJX74 SSSL library. Through pyramiding of the target genes, a restorer line, H121R, was developed. The H121R line was then improved regarding blast resistance by pyramiding of the qBLAST11 gene. Hence, a new restorer line with blast resistance, H131R, was developed. The platform involving the Rf34 and Rf44 restorer genes would be used for the continuous improvement of restorer lines through breeding by design in rice.