Phytopathology Research
·
2024
·Vol. 6
·期 1
·1-15
·
IF 3.2
Li Xiufang,Liu Zongling,Wu Haoming,Yu Zhuoxin,Meng Jiaorong,Zhao Haiyun,Deng Xingli,Su Yizu,Chen Baoshan,Li Ru
Sugarcane ( Saccharum spp.) is a major sucrose and bioenergy crop in the world. The fungal pathogen Sporisorium scitamineum causes sugarcane smut, a devastating disease that destroys stalks and reduces sugar content in sugarcane. This disease can be controlled most effectively by applying smut-resistant sugarcane varieties. Previous studies have shown that Dirigent (DIR ) genes are involved in the synthesis of the lignin precursor pinoresinol, which plays a crucial role in plant resistance to biotic stresses. However, the immune response of the DIR homologs in sugarcane ( ScDIR ) has not been reported yet. In this study, we found that the lignin content of smut-resistant sugarcane varieties (ZZ1, ZZ6, and ZZ9) was significantly higher than that of smut-susceptible varieties (GT42, ROC22, and FN41), and the lignin content of sugarcane increased after smut infection. The smut-resistant and smut-susceptible clones derived from the same genetic population (ROC25 × YZ89-7) showed similar patterns. Quantitative real-time PCR assays revealed that among the 64 DIR genes in sugarcane, ScDIR5 , ScDIR7 , ScDIR11 , and ScDIR40 showed elevated expression after S. scitamineum infection. In vitro coupling reactions showed that the four corresponding ScDIR proteins could mediate the coupling of coniferyl alcohol and its conversion into the lignin precursor pinoresinol. Overexpression of the four ScDIR genes in Nicotiana benthamiana enhanced disease resistance to the fungal pathogens Sclerotium rolfsii , Rhizoctonia solani , and Botrytis cinerea . Moreover, transgenic sugarcane overexpressing these ScDIR genes showed enhanced resistance to smut disease. Taken together, our findings provide evidence that sugarcane ScDIR genes can improve the resistance of plants to fungal pathogens and highlight their potentials in sugarcane breeding for disease resistance.
研究领域:
植物病理学
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分子生物学
·
遗传学
·
农业科学
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DOI
高影响因子
MOLECULAR PLANT PATHOLOGY
·
2024
·Vol. 25
·期 9
·e70003
·
IF 4.8
Kai Yin,Zhijian Hu,Meiting Yuan,Weidong Chen,Xinping Bi,Guobing Cui,Zhibin Liang,Yi Zhen Deng
Sugarcane smut fungus Sporisorium scitamineum produces polyamines putrescine (PUT), spermidine (SPD), and spermine (SPM) to regulate sexual mating/filamentous growth critical for pathogenicity. Besides de novo biosynthesis, intracellular levels of polyamines could also be modulated by oxidation. In this study, we identified two annotated polyamine oxidation enzymes (SsPAO and SsCuAO1) in S. scitamineum . Compared to the wild type ( MAT-1 ), the ss1pao Δ and ss1cuao1 Δ mutants were defective in sporidia growth, sexual mating/filamentation, and pathogenicity. The addition of a low concentration of cAMP (0.1 mM) could partially or fully restore filamentation of ss1pao Δ × ss2pao Δ or ss1cuao1 Δ × ss2cuao1 Δ. cAMP biosynthesis and hydrolysis genes were differentially expressed in the ss1pao Δ × ss2pao Δ or ss1cuao1 Δ × ss2cuao1 Δ cultures, further supporting that SsPAO- or SsCuAO1-based polyamine homeostasis regulates S. scitamineum filamentation by affecting the cAMP/PKA signalling pathway. During early infection, PUT promotes, while SPD inhibits, the accumulation of reactive oxygen species (ROS) in sugarcane, therefore modulating redox homeostasis at the smut fungus–sugarcane interface. Autophagy induction was found to be enhanced in the ss1pao Δ mutant and reduced in the ss1cuao1 Δ mutant. Exogenous addition of cAMP, PUT, SPD, or SPM at low concentration promoted autophagy activity under a non-inductive condition (rich medium), suggesting a cross-talk between polyamines and cAMP signalling in regulating autophagy in S. scitamineum . Overall, our work proves that SsPAO- and SsCuAO1-mediated intracellular polyamines affect intracellular redox balance and thus play a role in growth, sexual mating/filamentation, and pathogenicity of S. scitamineum .
研究领域:
真菌学
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植物病理学
·
分子生物学
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产品关联
DOI
PubMed
高影响因子
Plants-Basel
·
2026
·Vol. 15
·期 9
·1408
·
IF 4.7
Yangmin Zhu,Zengrong Huang,Junyi Wen,Jiangming Wei,Ke Liu,Yuan Su,Yunfeng Liu,Shengchao Ge
Papain-like cysteine proteases (PLCPs) are central immune hubs frequently targeted by pathogen effectors. Sugarcane smut, caused bySporisorium scitamineum, threatens global sugarcane yield, yet effector manipulation of host PLCPs remains unclear. Genome-wide analysis ofSaccharum spontaneumAP85-441 identified 61 PLCP-encoding genes, which were classified into nine conserved subfamilies. Among these, ScRD21A, a member of the RD21 subfamily, was prioritized for functional characterization. Two Pit2 homologs, SsPit2A and SsPit2B, were identified fromS. scitamineum. Yeast two-hybrid, BiFC and pull-down assays demonstrated that both effectors interact with ScRD21A, and that this interaction depends on a conserved LXRR motif within their PID14-like region. In total protein extracts fromNicotiana benthamiana, co-expression of SsPit2A or SsPit2B reduced ScRD21A-associated cysteine protease activity. Transient expression of ScRD21A enhanced flg22-induced ROS production, attenuatedPst DC3000-induced hypersensitive response-associated necrosis, and increased resistance toBotrytis cinerea. Together, these results support a conserved PLCP-targeting strategy in smut fungi and identify the ScRD21A–SsPit2A/B module as a tractable framework for studying effector–protease interactions relevant to sugarcane smut.
✓ 已验证
DOI
PubMed
高影响因子