Abstract
The actin cytoskeleton is a key player in defense responses during early stages of infection by fungal pathogens. To investigate molecular mechanisms of actin-related defense responses, a cultured tobacco (Nicotiana tabacum L.) BY-2 cell system was devised. When conidia were directly deposited on BY-2 cells, neither a pathogen, Erysiphe cichoracearum, nor a non-pathogen, Erysiphe pisi, was able to form appressoria or haustoria on BY-2 cells. On the other hand, conidia of the powdery mildews formed appressoria on BY-2 cells if they were covered with a thin hydrophobic membrane of Formvar. Percentages of appressoria formation of the powdery mildews on the Formvar-covered BY-2 cells were mostly the same as those on leaf epidermal cells. The pathogen successfully penetrated through the membrane into BY-2 cells and formed haustoria, whereas penetration attempts of the non-pathogen were completely rejected by the BY-2 cells similar to attempts on leaf epidermal cells. On the other hand, when BY-2 cells were treated with actin cytoskeleton-depolymerizing agents, cytochalasins, the non-pathogen became able to penetrate and form haustoria in BY-2 cells. Simultaneously, cytochalasin inhibited callose deposition at penetration sites of the non-pathogen. These results demonstrated that the actin cytoskeleton plays an important role in defense mechanisms against fungal penetration, even in the dedifferentiated cultured cells. The newly devised Formvar-covered cultured cell system will be a useful tool for molecular dissection of signal perception and defense mechanisms of plant cells during the early stage of fungal attack.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Adam L, Somerville SC (1996) Genetic characterization of five powdery mildew disease resistance loci in Arabidopsis thaliana. Plant J 9:341–356
Aist JR (1976) Papillae and related wound plugs of plant cells. Annu Rev Phytopathol 14:145–163
Bushnell WR, Bergquist S (1975) Aggregation of host cytoplasm and the formation of papillae and haustoria in powdery mildew of barley. Phytopathology 65:310–318
Carver TLW, Kunoh H, Thomas BJ, Nicholson RL (1999) Release and visualization of the extracellular matrix of conidia of Blumeria graminis. Mycol Res 103:547–560
Dickinson S (1979) Growth of Erysiphe graminis on artificial membranes. Physiol Plant Pathol 15:219–221
Gross P, Julius C, Schmelzer E, Hahlbrock K (1993) Translocation of cytoplasm and nucleus to fungal penetration sites is associated with depolymerization of microtubules and defense gene activation in infected, cultured parsley cells. EMBO J 12:1735–1744
Hammond-Kosack K, Jones JDG (2000) Responses to plant pathogens. In: Buchanan BB, Gruissem W, Jones RL (eds) Biochemistry & molecular biology of plants. American Society of Plant Physiologists, Rockville, MD, pp 1102–1156
Heim MJ, Gries GA (1953) The culture of Erysiphe cichoracearum on sunflower tumor tissues. Phytopathology 43:343–344
Heintz C (1986) Infection mechanisms of grapevine powdery mildew (Oideum tuckeri): comparable studies of the penetration process on artificial membranes and leaf epidermis. Vitis 25:215–225
Kobayashi I, Kobayashi Y (2000) Plant actin cytoskeletal responses to attack and invasion by pathogenic fungi. In: Staiger CJ, Baluska, F, Volkmann D, Barlow PW (eds). The actin cytoskeleton in plant cells. Kluwer, Dordrecht, pp 573–585
Kobayashi I, Tanaka C, Yamaoka N, Kunoh H (1991) Morphogenesis of Erysiphe graminis conidia on artificial membranes. Trans Mycol Soc Jpn 32:187–198
Kobayashi I, Kobayashi Y, Yamaoka N, Kunoh H (1992) Recognition of a pathogen and a nonpathogen by barley coleoptile cells. III. Responses of microtubules and actin filaments in barley coleoptile cells to penetration attempts. Can J Bot 70:1815–1823
Kobayashi Y, Kobayashi I, Funaki Y, Fujimoto S, Takemoto T, Kunoh H (1997a) Dynamic reorganization of microfilaments and microtubules is necessary for the expression of non-host resistance in barley coleoptile cells. Plant J 11:525–537
Kobayashi Y, Yamada M, Kobayashi I, Kunoh H (1997b) Actin microfilaments are required for the expression of nonhost resistance in higher plants. Plant Cell Physiol 38:725–733
Kunoh H, Toyoda H, Yamaoka N, Kobayashi I (1992) Morphogenesis of Erysiphe pisi conidia on artificial substrata. Trans Mycol Soc Jpn 33:87–93
McLusky SR, Bennett MH, Beale MH, Lewis MJ, Gaskin P, Mansfield JW (1999) Cell wall alterations and localized accumulation of feruloyl-3′-methoxytyramine in onion epidermis at sites of attempted penetration by Botrytis allii are associated with actin polymerization, peroxidase activity and suppression of flavonoid biosynthesis. Plant J 17:523–534
Nagata T, Nemoto Y, Hasezawa S (1992) Tobacco BY-2 cell line as the "HeLa" cell in the cell biology of higher plants. Int Rev Cytol 132:1-30
Naton B, Hahlbrock K, Schmelzer E (1996) Correlation of rapid cell death with metabolic changes in fungus-infected, cultured parsley cells. Plant Physiol 112:433–444
Schmelzer E (2002) Cell polarization, a crucial process in fungal defense. Trends Plant Sci 7:411–415
Schmelzer E, Naton B, Freytag S, Rouhara I, Kuster B, Hahlbrock K (1995) Infection-induced rapid cell death in plants: a means of efficient pathogen defense. Can J Bot [Suppl 1] 73:426–434
Singh UP, Singh HB (1981) Germination of Erysiphe polygoni conidia on pea callus tissues. Z Pflanzenkr Pflanzenpathol Pflanzenschutz 88:748–753
Sivapalan A (1993) Effects of water on germination of powdery mildew conidia. Mycol Res 97:71–76
Uchiyama T, Ogasawara N, Yokoyama K, Matsukawa M (1978) The culture of Erysiphe graminis f. sp. hordei on barley (Hordeum vulgare L.) callus and effect of moisture on germination of conidia. Bull Fac Agric Niigata Univ 30:51–62
Yamaoka N, Yamamoto T, Koabayshi I, Kunoh H (1994) Morphogenesis of the powdery mildew fungus in water (3). Decrease of the formation and penetration frequency of short germ tubes from water-immersed conidia of Erysiphe graminis. Ann Phytopathol Soc Jpn 60:636–639
Acknowledgement
We are grateful to Prof. Adrienne R. Hardham (Australian National University, Canberra, Australia) for correcting the text. This work was supported in part by Grant-in-Aid for Scientific Research No. 13660048 (2001, 2002) given to I.K.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Kobayashi, I., Hakuno, H. Actin-related defense mechanism to reject penetration attempt by a non-pathogen is maintained in tobacco BY-2 cells. Planta 217, 340–345 (2003). https://doi.org/10.1007/s00425-003-1042-3
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00425-003-1042-3