Dynamic Behavior of Superoxide Generation in Rice Leaf Tissue Infected with Blast Fungus and Its Regulation by Some Substances

Sekizawa, Yasuharu; Haga, Minoru; Hirabayashi, Emi; Takeuchi, Naoko; Takino, Yoshinori

doi:10.1080/00021369.1987.10868129

Cited by 15 publications

(22 citation statements)

References 1 publication

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“…1B). These three cellular events are typical cellular responses observed during R gene-mediated blast resistance in rice (26,27,31). None of these responses were found in untransformed control plants or transgenic plants expressing the dominantnegative OsRac1 (Fig.…”

Section: Resultsmentioning

confidence: 99%

Essential role of the small GTPase Rac in disease resistance of rice

Ono¹

2001

Proceedings of the National Academy of Sciences

154

155

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Production of reactive oxygen intermediates (ROI) and a form of programmed cell death called hypersensitive response (HR) are often associated with disease resistance of plants. We have previously shown that the Rac homolog of rice, OsRac1, is a regulator of ROI production and cell death in rice. Here we show that the constitutively active OsRac1 (i) causes HR-like responses and greatly reduces disease lesions against a virulent race of the rice blast fungus; (ii) causes resistance against a virulent race of bacterial blight; and (iii) causes enhanced production of a phytoalexin and alters expression of defense-related genes. The dominant-negative OsRac1 suppresses elicitor-induced ROI production in transgenic cell cultures, and in plants suppresses the HR induced by the avirulent race of the fungus. Taken together, our findings strongly suggest that OsRac1 has a general role in disease resistance of rice.

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Section: Resultsmentioning

confidence: 99%

Essential role of the small GTPase Rac in disease resistance of rice

Ono¹

2001

Proceedings of the National Academy of Sciences

154

155

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“…xylem and phloem (Hérouart et al, 1994;Ogawa et al, 1997). Wounded plant organs, in particular, can produce a burst of these oxygen intermediates (Salin and Bridges, 1981;Sekizawa et al, 1987). Recent results also show that H 2 O 2 present in vascular tissues may function as a systemic signal in wounding responses and systemic acquired resistance in Arabidopsis (Orozco-Cardenas and Ryan, 1999; S. Karpinski, unpublished data).…”

Section: Discussionmentioning

confidence: 97%

A Novel Superoxide Dismutase with a High Isoelectric Point in Higher Plants. Expression, Regulation, and Protein Localization

et al. 2001

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Several isoforms of superoxide dismutase (SOD) with a high isoelectric point (pI) have been identified by isoelectric focusing chromatography in protein extracts from Scots pine (Pinus sylvestris) needles. One of these isoforms, a CuZn-SOD with a pI of about 10 and thus denoted hipI-SOD, has been isolated and purified to apparent homogeneity. A cDNA encoding the hipI-SOD protein was cloned and sequenced. Northern hybridization of mRNA isolated from different organs and tissues showed that hipI-SOD has a markedly different pattern of expression compared with chloroplastic and cytosolic SOD. Furthermore, the transcript levels of hipI-SOD and cytosolic SOD were found to respond differently to mechanical wounding, treatment with oxidized glutathione, paraquat, and ozone. Immunogold electron microscopy localized the hipI-SOD in the plasma membrane of sieve cells and the Golgi apparatus of albuminous cells. Moreover, high protein density was also detected in extracellular spaces such as secondary cell wall thickenings of the xylem and sclerenchyma and in intercellular spaces of parenchyma cells.

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“…Sekizawa et al [109,110] have presented evidence for the generation of H0 2 /0 2 " in rice leaves infected by rice blast fungus (Pyricularia oryzae). While the time-course for this process appears curiously complex, 0 2~-generation occurred earlier and was larger in magnitude in response to incompatible infections compared to compatible infections.…”

Section: Fungal Pathogensmentioning

confidence: 99%