印度梨型孢真菌可增進水稻生長及鹽分/乾旱逆境之耐受性

Piriformospora indica Increases Rice Growth and Salt/Drought Stress Tolerance

林柏均(Po-Chun Lin)

指導教授 ： 王淑珍

國立臺灣大學/生物資源暨農學院/農藝學研究所/碩士(2014年)

https://doi.org/10.6342/NTU.2014.11179

摘要

在印度塔爾沙漠被發現的印度梨形孢真菌 (Piriformospora indica, P. indica) 為對植物具有正面效益的益生真菌，雖然在其他植物中已有許多研究觀察到P. indica之效用，但是詳細的機制仍需進一步研究。目前相關研究大多還是以阿拉伯芥為主，然而發表在大麥等穀類作物的研究逐年增加，說明此真菌具提升糧食作物生長勢之潛力。本研究針對水稻品種臺中在來一號 (Oryza sativa L. cv. Taichung Native 1, TCN1)，觀察真菌寄宿對其所產生之影響，結果發現接種P. indica使得TCN1之主根變短，而不定根的長度及數目則是有增加之趨勢。此外，雖主根上的側根數目減少，但側根長度卻仍呈現增長之現象。除了發現根系結構受P. indica寄宿而產生改變外，亦能觀察其地上部及根部鮮重有提升之趨勢。進一步觀察對植體內生長素 (auxin) 及乙烯 (ethylene) 反應之基因表現變化，發現這些基因表現皆會因接種P. indica而被誘導提升，推測生長素和乙烯可能參與在P. indica改變根系之調控機制中。另外在鹽分及乾旱逆境的實驗中說明，接種P. indica能維持寄主在逆境中的生長，結果指出P. indica可能透由抗氧化酵素活性的提升來清除逆境下生成的活性氧化物 (reactive oxygen spices, ROS)，增加水稻對逆境之耐受性。

關鍵字

水稻 (Oryza sativa L.) ； 印度梨形孢真菌 (Piriformospora indica) ； 鹽分逆境 ； 乾旱逆境

並列摘要

Piriformospora indica is a beneficial endophytic fungi for plants. Positive effects of P. indica on plant growth have been observed in several plant species, the mechanism of P. indica-promoted plant growth still need to be revealed. So far, most of the physiological responses of plants colonized by P. indica was observed in Arabidopsis. Some researches related to P. indica effect on cereal crops such as barley were published, and it was implied that P. indica colonization can be a powerful approach to improve crop production. Our works presented here was focused on the effect of P. indica on rice (Oryza sativa L. cv. Taichung Native 1, TCN1) growth and the abiotic stress tolerance. The result showed that P. indica reduced primary roots elongation. In addition, the total number and length of adventitious roots were also increased. Although the total number of lateral roots on primary roots was decreased, the length of total lateral roots was increased. In addition to the change of root architecture, the fresh weight of root systems was significantly increased in seedlings colonized by P. indica. Furthermore, we found that auxin- and ethylene-responsive genes in P. indica–colonized roots were up-regulated. Therefore, the level of auxin and ethylene might increase in colonized roots and participated in the P. indica-induced physiological pathway, but it still need some further study to confirm. Moreover, P. indica could help TCN1 to reduce the damage caused by salinity and drought stresses. Results showed that P. indica could up-regulate the antioxidant enzyme activities under stresses and environment recovery stage to enhance stress tolerance of rice plants.

並列關鍵字

rice (Oryza sativa L.) ； Piriformospora indica ； salt stress ； drought stress

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