28 January 2023, Volume 30 Issue 1 Previous Issue    Next Issue

    Research Paper
    For Selected: Toggle Thumbnails
    Rational Design of Grain Size to Improve Rice Yield and Quality
    Tao Yajun, Wang Jun, Xu Yang, Wang Fangquan, Li Wenqi, Jiang Yanjie, Chen Zhihui, Fan Fangjun, Zhu Jianping, Li Xia, Yang Jie
    2023, 30(1): 1-5.  DOI: 10.1016/j.rsci.2022.04.003
    Abstract ( )   HTML ( )   PDF (63392KB) ( )  
    Evaluation of Medicinal Plant Extracts for Rice Blast Disease Control
    Tan Yanping, Deng Shiqi, Qin Yonghua, Xu Xin, Yu You, Cui Liu, Wang Chuntai, Jiang Changjie, Liu Xinqiong
    2023, 30(1): 6-10.  DOI: 10.1016/j.rsci.2022.03.003
    Abstract ( )   HTML ( )   PDF (1549KB) ( )  
    Stay-Green Panicle Branches Improve Processing Quality of Elite Rice Cultivars
    Chen Yibo, Zhao Lei, Wang Chongrong, Li Hong, Huang Daoqiang, Wang Zhidong, Zhou Degui, Pan Yangyang, Gong Rong, Zhou Shaochuan
    2023, 30(1): 11-14.  DOI: 10.1016/j.rsci.2022.08.001
    Abstract ( )   HTML ( )   PDF (64651KB) ( )  
    Defensive Role of Plant Hormones in Advancing Abiotic Stress-Resistant Rice Plants
    M. Iqbal R. Khan, Sarika Kumari, Faroza Nazir, Risheek Rahul Khanna, Ravi Gupta, Himanshu Chhillar
    2023, 30(1): 15-35.  DOI: 10.1016/j.rsci.2022.08.002
    Abstract ( )   HTML ( )   PDF (5065KB) ( )  

    Consistent climatic perturbations have increased global environmental concerns, especially the impacts of abiotic stresses on crop productivity. Rice is a staple food crop for the majority of the world’s population. Abiotic stresses, including salt, drought, heat, cold and heavy metals, are potential inhibitors of rice growth and yield. Abiotic stresses elicit various acclimation responses that facilitate in stress mitigation. Plant hormones play an important role in mediating the growth and development of rice plants under optimal and stressful environments by activating a multitude of signalling cascades to elicit the rice plant’s adaptive responses. The current review describes the role of plant hormone-mediated abiotic stress tolerance in rice, potential crosstalk between plant hormones involved in rice abiotic stress tolerance and significant advancements in biotechnological initiatives including genetic engineering approach to provide a step forward in making rice resistance to abiotic stress.

    Research Paper
    Knocking-Out OsPDR7 Triggers Up-Regulation of OsZIP9 Expression and Enhances Zinc Accumulation in Rice
    Meng Lu, Tang Mingfeng, Zhu Yuxing, Tan Longtao
    2023, 30(1): 36-49.  DOI: 10.1016/j.rsci.2022.05.004
    Abstract ( )   HTML ( )   PDF (49005KB) ( )  

    Zinc (Zn) is an essential trace mineral that is required for plant growth and development. A number of protein transporters, which are involved in Zn uptake, translocation and distribution, are finely regulated to maintain Zn homeostasis in plant. In this study, we functionally characterized an ATP-binding cassette (ABC) transporter gene, OsPDR7, which is involved in Zn homeostasis. OsPDR7 encodes a plasma membrane-localized protein that is expressed mainly in the exodermis and xylem in the rice root. ospdr7 mutants resulted in higher Zn accumulation compared with the wild type. Heterogeneous expression of OsPDR7 in a yeast mutant rescued the Zn-deficiency phenotype, implying transport activity of OsPDR7 to Zn in yeast. However, no ZIP genes except for OsZIP9 showed change in expression profile in the ospdr7 mutants, which suggested that OsPDR7 maintains cellular Zn homeostasis through regulating OsZIP9 expression. RNA-Seq analysis further revealed a set of differentially expressed genes between the wild type and ospdr7 mutants that allowed us to propose a possible OsPDR7-associated signaling network involving transporters, hormone responsive genes, and transcription factors. Our results revealed a novel transporter involved in the regulation of Zn homeostasis and will pave the way toward a better understanding of the fine-tuning of gene expression in the network of transporter genes.

    bZIP Transcription Factor UvATF21 Mediates Vegetative Growth, Conidiation, Stress Tolerance and Is Required for Full Virulence of Rice False Smut Fungus Ustilaginoidea virens
    Liu Yueran, Qu Jinsong, Wang Yufu, Yin Weixiao, Luo Chaoxi
    2023, 30(1): 50-57.  DOI: 10.1016/j.rsci.2022.12.001
    Abstract ( )   HTML ( )   PDF (4137KB) ( )  

    bZIP proteins are widely distributed in eukaryotic organisms and regulate a diverse range of physiological processes. Several bZIP proteins have previously been identified in Ustilaginoidea virens. However, the biological roles of these bZIP proteins in this pathogen are still unknown. Here, one of these bZIP protein coding genes, UvATF21, was functionally characterized. Targeted deletion of UvATF21resulted in reduced conidiation and pathogenicity despite of the increased vegetative growth. The deletion mutants also significantly decreased the sensitivity to osmotic and oxidative stresses. Interestingly, deletion of UvATF21 exhibited different performances to cell wall integrity stress. These results indicated that UvATF21played crucial roles in vegetative growth, conidiation, stress response, and full virulence in U. virens.

    Differential Expression of Iron Deficiency Responsive Rice Genes under Low Phosphorus and Iron Toxicity Conditions and Association of OsIRO3 with Yield in Acidic Soils
    Ernieca Lyngdoh Nongbri, Sudip Das, Karma Landup Bhutia, Aleimo G. Momin, Mayank Rai, Wricha Tyagi
    2023, 30(1): 58-69.  DOI: 10.1016/j.rsci.2022.07.009
    Abstract ( )   HTML ( )   PDF (5979KB) ( )  

    With the hypothesis that iron (Fe) deficiency responsive genes may play a role in Fe toxicity conditions, we studied five such genes OsNAS1, OsNAS3, OsIRO2, OsIRO3 and OsYSL16 across six contrasting rice genotypes for expression under high Fe and low phosphorus (P) conditions, and sequence polymorphism. Genotypes Sahbhagi Dhan, Chakhao Poirieton and Shasharang were high yielders with no bronzing symptom visible under Fe toxic field conditions, and BAM350 and BAM811 were low yielders but did not show bronzing symptoms. Hydroponic screening revealed that the number of crown roots and root length can be traits for consideration for identifying Fe toxicity tolerance in rice genotypes. Fe contents in rice roots and shoots of a high-yielding genotype KMR3 showing leaf bronzing were significantly high. In response to 24 h high Fe stress, the expression levels of OsNAS3 were up-regulated in all genotypes except KMR3. In response to 48 h high Fe stress, the expression levels of OsNAS1 were 3-fold higher in tolerant Shasharang, whereas in KMR3, it was significantly down-regulated. Even in response to 7 d excess Fe stress, the transcript abundances of OsIRO2 and OsNAS3 were contrasting in genotypes Shasharang and KMR3. This suggested that the reported Fe deficiency genes had a role in Fe toxicity and that in genotype KMR3 under excess Fe stress, there was disruption of metal homeostasis. Under the 48 h low P conditions, OsIRO2 and OsYSL16 were significantly up-regulated in Fe tolerant genotype Shasharang and in low P tolerant genotype Chakhao Poirieton, respectively. In silico sequence analysis across 3 024 rice genotypes revealed polymorphism for 4 genes. Sequencing across OsIRO3 and OsNAS3 revealed nucleotide polymorphism between tolerant and susceptible genotypes for Fe toxicity. Non-synonymous single nucleotide polymorphisms and insertion/deletions (InDels) differing in tolerant and susceptible genotypes were identified. A marker targeting 25-bp InDel in OsIRO3, when run on a diverse panel of 43 rice genotypes and a biparental population, was associated with superior performance for yield under acidic lowland field conditions. This study highlights the potential of one of the vital genes involved in Fe homeostasis as a genic target for improving rice yield in acidic soils.

    Brassinosteroids Mediate Endogenous Phytohormone Metabolism to Alleviate High Temperature Injury at Panicle Initiation Stage in Rice
    Chen Yanhua, Wang Yaliang, Chen Huizhe, Xiang Jing, Zhang Yikai, Wang Zhigang, Zhu Defeng, Zhang Yuping
    2023, 30(1): 70-86.  DOI: 10.1016/j.rsci.2022.05.005
    Abstract ( )   HTML ( )   PDF (3697KB) ( )  

    High temperatures cause physiological and biochemical changes and significantly affect young panicle development of rice (Oryza sativa L.). Brassinosteroids play important roles in enhancing crop stress resistance. In this study, we subjected rice cultivars Huanghuazhan (heat-resistant) and IR36 (heat-sensitive) to high temperature (HT, 40 oC) or normal temperature (NT, 33 oC) for 7 d at the panicle initiation stage, in conjunction with application of 24-epibrassinolide [EBR, a synthetic brassinolide (BR)] or brassinazole (BRZ, a BR biosynthesis inhibitor) at the beginning of the treatments. HT exacerbated spikelet degeneration and inhibited young panicle growth, which were partially prevented by EBR application, while BRZ application aggravated the reduction in spikelet number. HT decreased the contents of BR, active cytokinins (aCTK), active gibberellins (aGA) and indole-3-acetic acid (IAA), but increased the content of abscisic acid (ABA) in young panicles. The activities of key enzymes involved in sucrose hydrolysis, glycolysis and the tricarboxylic acid cycle in young panicles were decreased with the change of endogenous hormone levels under HT. In addition, the contents of H2O2 and malondialdehyde (MDA) were increased and the activities of antioxidant enzymes were decreased in young panicles. Exogenous application of EBR induced the expression of phytohormone biosynthesis-related genes and down-regulated the expression of phytohormone catabolism-related genes to increase the contents of endogenous BR, aCTK, aGA and ABA, thus promoting the decomposition and utilization of sucrose in young panicles, enhancing the activities of superoxide dismutase, catalase and peroxidase, and reducing the accumulation of H2O2 and MDA in young panicles, whereas application of BRZ had the opposite physiological effects. These results showed that brassinosteroids mediate endogenous phytohormone metabolism to alleviate HT injury at the panicle initiation stage in rice.