Control of Plant Height and Lateral Root Development via Stu-miR156 Regulation of SPL9 Transcription Factor in Potato.

MicroRNAs (miRNAs) are a class of endogenous, non-coding small-molecule RNAs that usually regulate the expression of target genes at the post-transcriptional level. miR156 is one of a class of evolutionarily highly conserved miRNA families. SQUAMOSA PROMOTER BINDING PROTEIN-LIKE (SPL) transcription factor is one of the target genes that is regulated by miR156. SPL transcription factors are involved in regulating plant growth and development, hormone response, stress response, and photosynthesis. In the present study, transgenic potato plants with overexpressed miR156 were obtained via the Agrobacterium-mediated transformation method. The results showed that the expression levels of the target gene, StSPL9, were all downregulated in the transgenic plants with overexpressed Stu-miR156. Compared with those of the control plants, the plant height and root length of the transgenic plants were significantly decreased, while the number of lateral roots was significantly increased. These results revealed that the miR156/SPLs module was involved in regulating potato plant height and root growth.

Role of bZIP Transcription Factors in Plant Salt Stress.

Soil salinity has become an increasingly serious problem worldwide, greatly limiting crop development and yield, and posing a major challenge to plant breeding. Basic leucine zipper (bZIP) transcription factors are the most widely distributed and conserved transcription factors and are the main regulators controlling various plant response processes against external stimuli. The bZIP protein contains two domains: a highly conserved, DNA-binding alkaline region, and a diverse leucine zipper, which is one of the largest transcription factor families in plants. Plant bZIP is involved in many biological processes, such as flower development, seed maturation, dormancy, and senescence, and plays an important role in abiotic stresses such as salt damage, drought, cold damage, osmotic stress, mechanical damage, and ABA signal response. In addition, bZIP is involved in the regulation of plant response to biological stresses such as insect pests and pathogen infection through salicylic acid, jasmonic acid, and ABA signal transduction pathways. This review summarizes and discusses the structural characteristics and functional characterization of the bZIP transcription factor group, the bZIP transcription factor complex and its molecular regulation mechanisms related to salt stress resistance, and the regulation of transcription factors in plant salt stress resistance. This review provides a theoretical basis and research ideas for further exploration of the salt stress-related functions of bZIP transcription factors. It also provides a theoretical basis for crop genetic improvement and green production in agriculture.

Fine mapping of the grain chalkiness quantitative trait locus qCGP6 reveals the involvement of Wx in grain chalkiness formation.

Grain chalkiness is an important index of rice appearance quality and is negatively associated with rice processing and eating quality. However, the genetic mechanism underlying chalkiness formation is largely unknown. To identify the genetic basis of chalkiness, 410 recombinant inbred lines (RILs) derived from two representative indica rice varieties, Shuhui498 (R498) and Yihui3551 (R3551), were used to discover quantitative trait loci (QTLs). The two parental lines and RILs were grown in three locations in China under three controlled fertilizer application levels. Analyses indicated that chalkiness was significantly affected by genotype, the environment, and the interaction between the two, and that heritability was high. Several QTLs were isolated, including the two stable QTLs qCGP6 and qCGP8. Fine mapping and candidate gene verification of qCGP6 showed that Wx may play a key role in chalkiness formation. Chromosomal segment substitution lines (CSSLs) and near-isogenic lines (NILs) carrying the Wxa or Wxin allele produced more chalky grain than the R498 parent. A similar result was also observed in the 3611 background. Notably, the effect of the Wx genotype on rice chalkiness was shown to be dependent on environmental conditions, and Wx alleles exhibited different sensitivities to shading treatment. Using clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated 9 (Cas9), the Wxa promoter region was successfully edited; down-regulating Wx alleviates chalkiness formation in NILR498-Wxa. This study developed a new strategy for synergistic improvement of eating and appearance qualities in rice, and created a novel Wx allele with great potential in breeding applications.

Gradual daylength sensing coupled with optimum cropping modes enhances multi-latitude adaptation of rice and maize.

To expand crop planting areas, reestablishment of crop latitude adaptation based on genetic variation in photoperiodic genes can be performed, but it is quite time consuming. By contrast, a crop variety that already exhibits multi-latitude adaptation has the potential to increase its planting areas to be more widely and quickly available. However, the importance and potential of multi-latitude adaptation of crop varieties have not been systematically described. Here, combining daylength-sensing data with the cropping system of elite rice and maize varieties, we found that varieties with gradual daylength sensing coupled with optimum cropping modes have an enhanced capacity for multi-latitude adaptation in China. Furthermore, this multi-latitude adaptation expanded their planting areas and indirectly improved China's nationwide rice and maize unit yield. Thus, coupling the daylength-sensing process with optimum cropping modes to enhance latitude adaptability of excellent varieties represents an exciting approach for deploying crop varieties with the potential to expand their planting areas and quickly improve nationwide crop unit yield in developing countries.

Stu-miR827-Targeted StWRKY48 Transcription Factor Negatively Regulates Drought Tolerance of Potato by Increasing Leaf Stomatal Density.

Stomata are specialized portals in plant leaves to modulate water loss from plants to the atmosphere by control of the transpiration, thereby determining the water-use efficiency and drought resistance of plants. Despite that the stomata developmental progression is well-understood at the molecular level, the experimental evidence that miRNA regulates stomata development is still lacking, and the underlying mechanism remains elusive. This study demonstrates the involvement of stu-miR827 in regulating the drought tolerance of potato due to its control over the leaf stomatal density. The expression analysis showed that stu-miR827 was obviously repressed by drought stresses and then rapidly increased after rewatering. Suppressing the expression of stu-miR827 transgenic potato lines showed an increase in stomatal density, correlating with a weaker drought resistance compared with wildtype potato lines. In addition, StWRKY48 was identified as the target gene of stu-miR827, and the expression of StWRKY48 was obviously induced by drought stresses and was greatly upregulated in stu-miR827 knockdown transgenic potato lines, suggesting its involvement in the drought stress response. Importantly, the expression of genes associated with stomata development, such as SDD (stomatal density and distribution) and TMM (too many mouths), was seriously suppressed in transgenic lines. Altogether, these observations demonstrated that suppression of stu-miR827 might lead to overexpression of StWRKY48, which may contribute to negatively regulating the drought adaptation of potato by increasing the stomatal density. The results may facilitate functional studies of miRNAs in the process of drought tolerance in plants.

Wide Grain 3, a GRAS Protein, Interacts with DLT to Regulate Grain Size and Brassinosteroid Signaling in Rice.

BACKGROUND: Grain size is a direct determinant of grain weight and yield in rice; however, the genetic and molecular mechanisms determining grain size remain largely unknown. FINDINGS: We identified a mutant, wide grain 3 (wg3), which exhibited significantly increased grain width and 1000-grain weight. Cytological analysis showed that WG3 regulates grain size by affecting cell proliferation. MutMap-based gene cloning and a transgenic experiment demonstrated that WG3 encodes a GRAS protein. Moreover, we found that WG3 directly interacts with DWARF AND LOW-TILLERING (DLT), a previously reported GRAS protein, and a genetic experiment demonstrated that WG3 and DLT function in a common pathway to regulate grain size. Additionally, a brassinosteroid (BR) sensitivity test suggested that WG3 has a positive role in BR signaling in rice. Collectively, our results reveal a new genetic and molecular mechanism for the regulation of grain size in rice by the WG3-DLT complex, and highlight the important functions of the GRAS protein complex in plants. CONCLUSION: WG3 functions directly in regulating grain size and BR signaling in rice.

Overproduction of OsRACK1A, an effector-targeted scaffold protein promoting OsRBOHB-mediated ROS production, confers rice floral resistance to false smut disease without yield penalty.

Grain formation is fundamental for crop yield but is vulnerable to abiotic and biotic stresses. Rice grain production is threatened by the false smut fungus Ustilaginoidea virens, which specifically infects rice floral organs, disrupting fertilization and seed formation. However, little is known about the molecular mechanisms of the U. virens-rice interaction and the genetic basis of floral resistance. Here, we report that U. virens secretes a cytoplasmic effector, UvCBP1, to facilitate infection of rice flowers. Mechanistically, UvCBP1 interacts with the rice scaffold protein OsRACK1A and competes its interaction with the reduced nicotinamide adenine dinucleotide phosphate oxidase OsRBOHB, leading to inhibition of reactive oxygen species (ROS) production. Although the analysis of natural variation revealed no OsRACK1A variants that could avoid being targeted by UvCBP1, expression levels of OsRACK1A are correlated with field resistance against U. virens in rice germplasm. Overproduction of OsRACK1A restores the OsRACK1A-OsRBOHB association and promotes OsRBOHB phosphorylation to enhance ROS production, conferring rice floral resistance to U. virens without yield penalty. Taken together, our findings reveal a new pathogenic mechanism mediated by an essential effector from a flower-specific pathogen and provide a valuable genetic resource for balancing disease resistance and crop yield.

Calcium-Dependent Protein Kinase 28 Maintains Potato Photosynthesis and Its Tolerance under Water Deficiency and Osmotic Stress.

Calcium-dependent protein kinases (CDPK) are implicated in signaling transduction in eukaryotic organisms. It is largely unknown whether StCDPK28 plays a role in the response to water deficiency and osmotic stress in potato plants (Solanum tuberosum L.). Potato cv. Zihuabai was cultivated under natural, moderate, and severe water deficiency conditions; to induce osmotic stress, potato plants were treated with 10% or 20% PEG. StCDPK28-overexpression and StCDPK28-knockdown plants were constructed. StCDPKs were evaluated by qRT-PCR. The subcellular location of the StCDPK28 protein was observed with confocal scanning laser microscopy. Phenotypic changes were indicated by photosynthetic activity, the contents of H2O2, MDA and proline, and the activities of CAT, SOD and POD. Results showed water deficiency and osmotic stress altered StCDPK expression patterns. StCDPK28 exhibited a membrane, cytosolic and nuclear localization. Water deficiency and osmotic stress induced StCDPK28 upregulation. Photosynthetic activity was enhanced by StCDPK28 overexpression, while decreased by StCDPK2 knockdown under water deficiency and osmotic stress. StCDPK28 overexpression decreased H2O2 and MDA, and increased proline, while StCDPK28 knockdown showed reverse results, compared with the wild type, in response to water deficiency and osmotic stress. StCDPK28 overexpression increased the activities of CAT, SOD and POD, while StCDPK28-knockdown plants indicated the reverse trend under water deficiency and osmotic stress conditions. Regulation of StCDPK28 expression could be a promising approach to improve the tolerance ability of potato plants in response to drought or high salt media.

Short grain 5 controls grain length in rice by regulating cell expansion.

Grain shape is a crucial determinant of grain weight and quality and plays a vital role in rice breeding. Although many grain shape-related genes have been reported, the regulatory relationship between them has not been well characterized in rice. In this study, we report the isolation of a short-grain-length mutant called sg5 from the heavy-panicle-type hybrid rice elite restorer line 'ShuhuiR498' (R498) after ethyl methanesulfonate (EMS) treatment. MutMap cloning revealed that SG5 encodes a Myb-like transcription factor. A missense mutation in the first exon of SG5 was found to cause an amino acid change from leucine to proline at position 197 in the mutant SG5 protein. Gene knockout and genetic complementation experiments confirmed that the point mutation in SG5 was responsible for the sg5 mutant phenotype. SG5 is mainly expressed in young panicles and hulls. In addition, the SG5 protein is found in the nucleus and does not affect subcellular localization. Histochemical observation and gene expression analysis indicated that SG5 regulates spikelet hull development by mediating cell expansion. Moreover, the expression levels of BG1, GS2, and DEP1 were reduced in sg5 plants, and dual-luciferase (LUC) assays showed that SG5 can bind to the BG1 gene promoter. The effect of pyramiding sg5 and GS3 suggests that sg5 and GS3 regulate grain length independently. The results of our study show that the missense mutation in sg5 is essential for the molecular function of SG5 and SG5 is involved in regulating cell expansion and expression of grain-shape-related genes to regulate grain length. This work provides new data to help study and understand the molecular function of SG5.

OsBSK2, a putative brassinosteroid-signalling kinase, positively controls grain size in rice.

Grain size is an important trait that directly affects grain yield in rice; however, the genetic and molecular mechanisms regulating grain size remain unclear. In this study, we identified a mutant, grain length and grain weight 10 (glw10), which exhibited significantly reduced grain length and grain weight. Histological analysis demonstrated that GLW10 affects cell expansion, which regulates grain size. MutMap-based gene mapping and transgenic experiments demonstrated that GLW10 encodes a putative brassinosteroid (BR) signalling kinase, OsBSK2. OsBSK2 is a plasma membrane protein, and an N-myristoylation site is needed for both membrane localization and function. OsBSK2 directly interacts with the BR receptor kinase OsBRI1; however, genetic experiments have demonstrated that OsBSK2 may regulate grain size independent of the BR signalling pathway. OsBSK2 can form a homodimer or heterodimer with OsBSK3 and OsBSK4, and silencing OsBSK2, OsBSK3, and OsBSK4 reduce grain size. This indicates that OsBSKs seem to function as homodimers or heterodimers to positively regulate grain size in rice. OsBSK2/3/4 are all highly expressed in young panicles and spikelet hulls, suggesting that they control grain size. In summary, our results provide novel insights into the function of BSKs in rice, and identify novel targets for improving grain size during crop breeding.

Rice NIN-LIKE PROTEIN 3 modulates nitrogen use efficiency and grain yield under nitrate-sufficient conditions.

Nitrogen (N) is an essential macronutrient for crop growth and yield. Improving the N use efficiency (NUE) of crops is important to agriculture. However, the molecular mechanisms underlying NUE regulation remain largely elusive. Here we report that the OsNLP3 (NIN-like protein 3) regulates NUE and grain yield in rice under N sufficient conditions. OsNLP3 transcript level is significantly induced by N starvation and its protein nucleocytosolic shuttling is specifically regulated by nitrate. Loss-of-function of OsNLP3 reduces plant growth, grain yield, and NUE under sufficient nitrate conditions, whereas under low nitrate or different ammonium conditions, osnlp3 mutants show no clear difference from the wild type. Importantly, under sufficient N conditions in the field, OsNLP3 overexpression lines display improved grain yield and NUE compared with the wild type. OsNLP3 orchestrates the expression of multiple N uptake and assimilation genes by directly binding to the nitrate-responsive cis-elements in their promoters. Overall, our study demonstrates that OsNLP3, together with OsNLP1 and OsNLP4, plays overlapping and differential roles in N acquisition and NUE, and modulates NUE and the grain yield increase promoted by N fertilizer. Therefore, OsNLP3 is a promising candidate gene for the genetic improvement of grain yield and NUE in rice.

Fine mapping and candidate gene analysis of qGSN5, a novel quantitative trait locus coordinating grain size and grain number in rice.

KEY MESSAGE: qGSN5, a novel quantitative trait locus coordinating grain size and grain number in rice, was fine-mapped to an 85.60-kb region. GS3 may be a suppressor of qGSN5. Grain size and grain number are two factors that directly determine rice grain yield; however, the underlying genetic mechanisms are complicated and remain largely unclear. In this study, a chromosome segment substitution line (CSSL), CSSL28, which showed increased grain size and decreased grain number per panicle, was identified in a set of CSSLs derived from a cross between 93-11 (recipient) and Nipponbare (donor). Four substitution segments were identified in CSSL28, and the substitution segment located on chromosome 5 was responsible for the phenotypes of CSSL28. Thus, we defined this quantitative trait locus (QTL) as grain size and grain number 5 (qGSN5). Cytological and quantitative PCR analysis showed that qGSN5 regulates the development of the spikelet hull by affecting cell proliferation. Genetic analysis showed that qGSN5 is a semi-dominant locus regulating grain size and grain number. Through map-based cloning and overlapping substitution segment analysis, qGSN5 was finally delimited to an 85.60-kb region. Based on sequence and quantitative PCR analysis, Os05g47510, which encodes a P-type pentatricopeptide repeat protein, is the most likely candidate gene for qGSN5. Pyramiding analysis showed that the effect of qGSN5 was significantly lower in the presence of a functional GS3 gene, indicating that GS3 may be a suppressor of qGSN5. In addition, we found that qGSN5 could improve the grain shape of hybrid rice. Together, our results lay the foundation for cloning a novel QTL coordinating grain size and grain number in rice and provide a good genetic material for long-grain hybrid rice breeding.

Loss of Gn1a/OsCKX2 confers heavy-panicle rice with excellent lodging resistance.

Significant achievements have been made in breeding programs for the heavy-panicle-type (HPT) rice (Oryza sativa) in Southwest China. The HPT varieties now exhibit excellent lodging resistance, allowing them to overcome the greater pressures caused by heavy panicles. However, the genetic mechanism of this lodging resistance remains elusive. Here, we isolated a major quantitative trait locus, Panicle Neck Diameter 1 (PND1), and identified the causal gene as GRAIN NUMBER 1A/CYTOKININ OXIDASE 2 (Gn1A/OsCKX2). The null gn1a allele from rice line R498 (gn1aR498 ) improved lodging resistance through increasing the culm diameter and promoting crown root development. Loss-of-function of Gn1a/OsCKX2 led to cytokinin accumulation in the crown root tip and accelerated the development of adventitious roots. Gene pyramiding between the null gn1aR498 allele with two gain-of-function alleles, STRONG CULM 2 (SCM2) and SCM3, further improved lodging resistance. Moreover, Gn1a/OsCKX2 had minimal influence on overall rice quality. Our research thus highlights the distinct genetic components of lodging resistance of HPT varieties and provides a strategy for tailor-made crop improvement of both yield and lodging resistance in rice.

From Green Super Rice to green agriculture: Reaping the promise of functional genomics research.

Producing sufficient food with finite resources to feed the growing global population while having a smaller impact on the environment has always been a great challenge. Here, we review the concept and practices of Green Super Rice (GSR) that have led to a paradigm shift in goals for crop genetic improvement and models of food production for promoting sustainable agriculture. The momentous achievements and global deliveries of GSR have been fueled by the integration of abundant genetic resources, functional gene discoveries, and innovative breeding techniques with precise gene and whole-genome selection and efficient agronomic management to promote resource-saving, environmentally friendly crop production systems. We also provide perspectives on new horizons in genomic breeding technologies geared toward delivering green and nutritious crop varieties to further enhance the development of green agriculture and better nourish the world population.

Genome-Wide Identification, Characterization and Expression Analysis of the CIPK Gene Family in Potato (Solanum tuberosum L.) and the Role of StCIPK10 in Response to Drought and Osmotic Stress.

The potato (Solanum tuberosum L.), one of the most important food crops worldwide, is sensitive to environmental stresses. Sensor-responder complexes comprising calcineurin B-like (CBL) proteins and CBL-interacting protein kinases (CIPKs) not only modulate plant growth and development but also mediate numerous stress responses. Here, using a Hidden Markov Model and BLAST searches, 27 CIPK genes were identified in potato and divided into five groups by phylogenetic analysis and into two clades (intron-poor and intron-rich) by gene structure analysis. Quantitative reverse-transcription PCR (qRT-PCR) assays revealed that StCIPK genes play important roles in plant growth, development and abiotic stress tolerance. Up-regulated expression of StCIPK10 was significantly induced by drought, PEG6000 and ABA. StCIPK10 enhances both the ability of potato to scavenge reactive oxygen species and the content of corresponding osmoregulation substances, thereby strengthening tolerance to drought and osmotic stress. StCIPK10 is located at the intersection between the abscisic acid and abiotic stress signaling pathways, which control both root growth and stomatal closure in potato. In addition, StCIPK10 interacts with StCBL1, StCBL4, StCBL6, StCBL7, StCBL8, StCBL11 and StCBL12, and is specifically recruited to the plasma membrane by StCBL11.

Genome-Wide Analysis of NF-Y Genes in Potato and Functional Identification of StNF-YC9 in Drought Tolerance.

The nuclear factor Y (NF-Y) family is comprised of transcription factors that have been implicated in multiple plant biological processes. However, little is known about this family in potato. In the present study, a total of 41 StNF-Y genes were identified in the potato genome. In addition, the phylogenetic, gene structure, motif, and chromosomal location of this family were analyzed. The tissue expression profiles based on RNA-seq data showed that 27 StNF-Y genes had tissue-specific expression, while the remaining 14 had low expression in all tissues. Publicly available transcriptomics data from various abiotic stresses revealed several stress-responsive StNF-Y genes, which were further verified via quantitative real-time polymerase chain reaction experiments. Furthermore, the StNF-YC9 gene was highly induced by dehydration and drought treatments. StNF-YC9 protein was mainly localized in the nucleus and cytoplasmic membrane. Overexpressing StNF-YC9 potato lines (OxStNF-YC9) had significantly increased in root length and exhibited stronger stomatal closure in potato treated by polyethylene-glycol and abscisic acid. In addition, OxStNF-YC9 lines had higher photosynthetic rates and decreased water loss under short-term drought stress compared to wild-type plants. During long-term drought stress, OxStNF-YC9 lines had higher proline levels, lower malondialdehyde content, and increased activity of several antioxidant enzymes, including superoxide dismutase, catalase, and peroxidase. This study increased our understanding of the StNF-Y gene and suggested that StNF-YC9 played an important role in drought tolerance by increased the photosynthesis rate, antioxidant enzyme activity, and proline accumulation coupled to lowered malondialdehyde accumulation in potato.

Knockdown of MicroRNA160a/b by STTM leads to root architecture changes via auxin signaling in Solanum tuberosum.

The root phenotype is an important aspect of plant architecture and plays a critical role in plant facilitation of the extraction of water and nutrition from the soil. MicroRNAs (miRNAs) are classes of small RNAs with important roles in regulating endogenous gene expression at the post-transcriptional level that function in a range of plant development processes and in the response to abiotic stresses. However, little is known concerning the molecular mechanism of miRNAs in regulating the generation and development of plant root architecture. Herein, we demonstrated that potato miR160a/b acted as a critical regulator and affected plant root architecture by targeting the mRNA of StARF10 and StARF16 for cleavage. The miR160a/b precursor was cloned from potato. Quantitative PCR assays showed that the expression levels of miR160 and its targets were down- or up-regulated with the development of potato roots, respectively. Moreover, transgenic lines with suppressed stu-miR160 expression were established with the short tandem targets mimic (STTM), and the results showed that the ectopic expression of miR160a/b altered the levels of auxin and the expression of auxin signaling-related genes and caused drastic change in root architecture compared with that in control plants. Suppressing the expression of miR160 led to a severe reduction in root length, an increase in the number of lateral roots, and a decrease in fresh root weight in potato. Collectively, our data established a key role of miR160 in modulating plant root architecture in potato.

OsSPL9 Regulates Grain Number and Grain Yield in Rice.

Rice grain yield consists of several key components, including tiller number, grain number per panicle (GNP), and grain weight. Among them, GNP is mainly determined by panicle branches and spikelet formation. In this study, we identified a gene affecting GNP and grain yield, OsSPL9, which encodes SQUAMOSA-PROMOTER BINDING PROTEIN-LIKE (SPL) family proteins. The mutation of OsSPL9 significantly reduced secondary branches and GNP. OsSPL9 was highly expressed in the early developing young panicles, consistent with its function of regulating panicle development. By combining expression analysis and dual-luciferase assays, we further confirmed that OsSPL9 directly activates the expression of RCN1 (rice TERMINAL FLOWER 1/CENTRORADIALIS homolog) in the early developing young panicle to regulate the panicle branches and GNP. Haplotype analysis showed that Hap3 and Hap4 of OsSPL9 might be favorable haplotypes contributing to high GNP in rice. These results provide new insights on high grain number breeding in rice.

Pan-genome analysis of 33 genetically diverse rice accessions reveals hidden genomic variations.

Structural variations (SVs) and gene copy number variations (gCNVs) have contributed to crop evolution, domestication, and improvement. Here, we assembled 31 high-quality genomes of genetically diverse rice accessions. Coupling with two existing assemblies, we developed pan-genome-scale genomic resources including a graph-based genome, providing access to rice genomic variations. Specifically, we discovered 171,072 SVs and 25,549 gCNVs and used an Oryza glaberrima assembly to infer the derived states of SVs in the Oryza sativa population. Our analyses of SV formation mechanisms, impacts on gene expression, and distributions among subpopulations illustrate the utility of these resources for understanding how SVs and gCNVs shaped rice environmental adaptation and domestication. Our graph-based genome enabled genome-wide association study (GWAS)-based identification of phenotype-associated genetic variations undetectable when using only SNPs and a single reference assembly. Our work provides rich population-scale resources paired with easy-to-access tools to facilitate rice breeding as well as plant functional genomics and evolutionary biology research.

Suppression of rice miR168 improves yield, flowering time and immunity.

MicroRNA168 (miR168) is a key miRNA that targets Argonaute1 (AGO1), a major component of the RNA-induced silencing complex1,2. Previously, we reported that miR168 expression was responsive to infection by Magnaporthe oryzae, the causal agent of rice blast disease3. However, how miR168 regulates immunity to rice blast and whether it affects rice development remains unclear. Here, we report our discovery that the suppression of miR168 by a target mimic (MIM168) not only improves grain yield and shortens flowering time in rice but also enhances immunity to M. oryzae. These results were validated through repeated tests in rice fields in the absence and presence of rice blast pressure. We found that the miR168-AGO1 module regulates miR535 to improve yield by increasing panicle number, miR164 to reduce flowering time, and miR1320 and miR164 to enhance immunity. Our discovery demonstrates that changes in a single miRNA enhance the expression of multiple agronomically important traits.