CAJ | 학술논문

【目的】高浓度CO2在促进植物光合作用的同时,也诱导了叶片气孔关闭。气孔关闭降低植物的蒸腾作用,有助于提高水分利用效率和耐旱性。本文研究了高浓度CO2对番茄气孔开度和保卫细胞中一氧化氮( NO)含量的影响,以及NO信号分子在高浓度CO2诱导番茄气孔关闭的信号转导机制中的作用。为了确定NO的酶催化途径,本试验检测了一氧化氮合酶( nitric oxide synthase, NOS)和硝酸还原酶( nitrate reductase, NR)在高浓度CO2促进NO合成中的作用。【方法】本试验以番茄( Solanum lycocarpum L.)为研究材料,利用CO2培养箱( Conviron E7/2 growth chambers)提供不同CO2浓度的试验环境(将培养箱中CO2浓度控制为350μL/L或800μL/L),研究不同CO2浓度和试剂处理对番茄气孔开度和保卫细胞中NO含量的影响。采用NO特异性荧光探针DAF-FM DA检测番茄保卫细胞中NO的含量。 DAF-FM DA与NO反应生成一种荧光物质DAF-2 T,根据其荧光强度的高低可以判断NO的相对含量。利用NOS抑制剂L-NAME和NR抑制剂钨酸盐( tungstate),分别研究了NOS和NR在高浓度CO2促进NO合成中的作用。【结果】高浓度CO2处理6 h后,番茄气孔开度降至2．3μm,较正常气孔开度降低了32%。 NO荧光法检测发现,高浓度CO2处理导致保卫细胞的荧光强度显著增加,荧光强度升高了88%。当使用cPTIO清除NO后,保卫细胞中NO含量降低了35%；气孔开度恢复至3．2μm,基本上达到正常浓度CO2处理下的气孔开度。在高浓度CO2下,200μmol/L L-NAME处理导致气孔开度增加了30%,保卫细胞中NO含量降低了33%；100μmol/L钨酸盐处理导致气孔开度增加了35%,保卫细胞中NO含量降低了40%。【结论】本文发现高浓度CO2显著提高保卫细胞中NO含量和诱导气孔关闭,清除NO后则明显抑制气孔关闭,表明NO在诱导气孔关闭过程中起重要作用。药理学实验显示,使用NOS抑制剂L-NAME和NR抑制剂钨酸盐均可显著降低NO含量和抑制气孔关闭,表明NOS和NR均参与了高浓度CO2诱导保卫细胞中NO的合成过程。因此,认为高浓度CO2通过NOS和NR路径促进保卫细胞中NO的合成,提高了保卫细胞中NO含量,从而诱导了番茄气孔关闭。【目的】高濃度CO2在促進植物光閤作用的同時,也誘導瞭葉片氣孔關閉。氣孔關閉降低植物的蒸騰作用,有助于提高水分利用效率和耐旱性。本文研究瞭高濃度CO2對番茄氣孔開度和保衛細胞中一氧化氮( NO)含量的影響,以及NO信號分子在高濃度CO2誘導番茄氣孔關閉的信號轉導機製中的作用。為瞭確定NO的酶催化途徑,本試驗檢測瞭一氧化氮閤酶( nitric oxide synthase, NOS)和硝痠還原酶( nitrate reductase, NR)在高濃度CO2促進NO閤成中的作用。【方法】本試驗以番茄( Solanum lycocarpum L.)為研究材料,利用CO2培養箱( Conviron E7/2 growth chambers)提供不同CO2濃度的試驗環境(將培養箱中CO2濃度控製為350μL/L或800μL/L),研究不同CO2濃度和試劑處理對番茄氣孔開度和保衛細胞中NO含量的影響。採用NO特異性熒光探針DAF-FM DA檢測番茄保衛細胞中NO的含量。 DAF-FM DA與NO反應生成一種熒光物質DAF-2 T,根據其熒光彊度的高低可以判斷NO的相對含量。利用NOS抑製劑L-NAME和NR抑製劑鎢痠鹽( tungstate),分彆研究瞭NOS和NR在高濃度CO2促進NO閤成中的作用。【結果】高濃度CO2處理6 h後,番茄氣孔開度降至2．3μm,較正常氣孔開度降低瞭32%。 NO熒光法檢測髮現,高濃度CO2處理導緻保衛細胞的熒光彊度顯著增加,熒光彊度升高瞭88%。噹使用cPTIO清除NO後,保衛細胞中NO含量降低瞭35%；氣孔開度恢複至3．2μm,基本上達到正常濃度CO2處理下的氣孔開度。在高濃度CO2下,200μmol/L L-NAME處理導緻氣孔開度增加瞭30%,保衛細胞中NO含量降低瞭33%；100μmol/L鎢痠鹽處理導緻氣孔開度增加瞭35%,保衛細胞中NO含量降低瞭40%。【結論】本文髮現高濃度CO2顯著提高保衛細胞中NO含量和誘導氣孔關閉,清除NO後則明顯抑製氣孔關閉,錶明NO在誘導氣孔關閉過程中起重要作用。藥理學實驗顯示,使用NOS抑製劑L-NAME和NR抑製劑鎢痠鹽均可顯著降低NO含量和抑製氣孔關閉,錶明NOS和NR均參與瞭高濃度CO2誘導保衛細胞中NO的閤成過程。因此,認為高濃度CO2通過NOS和NR路徑促進保衛細胞中NO的閤成,提高瞭保衛細胞中NO含量,從而誘導瞭番茄氣孔關閉。
【목적】고농도CO2재촉진식물광합작용적동시,야유도료협편기공관폐。기공관폐강저식물적증등작용,유조우제고수분이용효솔화내한성。본문연구료고농도CO2대번가기공개도화보위세포중일양화담( NO)함량적영향,이급NO신호분자재고농도CO2유도번가기공관폐적신호전도궤제중적작용。위료학정NO적매최화도경,본시험검측료일양화담합매( nitric oxide synthase, NOS)화초산환원매( nitrate reductase, NR)재고농도CO2촉진NO합성중적작용。【방법】본시험이번가( Solanum lycocarpum L.)위연구재료,이용CO2배양상( Conviron E7/2 growth chambers)제공불동CO2농도적시험배경(장배양상중CO2농도공제위350μL/L혹800μL/L),연구불동CO2농도화시제처리대번가기공개도화보위세포중NO함량적영향。채용NO특이성형광탐침DAF-FM DA검측번가보위세포중NO적함량。 DAF-FM DA여NO반응생성일충형광물질DAF-2 T,근거기형광강도적고저가이판단NO적상대함량。이용NOS억제제L-NAME화NR억제제오산염( tungstate),분별연구료NOS화NR재고농도CO2촉진NO합성중적작용。【결과】고농도CO2처리6 h후,번가기공개도강지2．3μm,교정상기공개도강저료32%。 NO형광법검측발현,고농도CO2처리도치보위세포적형광강도현저증가,형광강도승고료88%。당사용cPTIO청제NO후,보위세포중NO함량강저료35%；기공개도회복지3．2μm,기본상체도정상농도CO2처리하적기공개도。재고농도CO2하,200μmol/L L-NAME처리도치기공개도증가료30%,보위세포중NO함량강저료33%；100μmol/L오산염처리도치기공개도증가료35%,보위세포중NO함량강저료40%。【결론】본문발현고농도CO2현저제고보위세포중NO함량화유도기공관폐,청제NO후칙명현억제기공관폐,표명NO재유도기공관폐과정중기중요작용。약이학실험현시,사용NOS억제제L-NAME화NR억제제오산염균가현저강저NO함량화억제기공관폐,표명NOS화NR균삼여료고농도CO2유도보위세포중NO적합성과정。인차,인위고농도CO2통과NOS화NR로경촉진보위세포중NO적합성,제고료보위세포중NO함량,종이유도료번가기공관폐。
[Objectives]Elevated CO2 has been shown to play a role in enhancing the photosynthesis of plants, and induce stomatal closure of leaf. Stomatal closure significantly decreases plant transpiration, and contributes to enhanced water use efficiency and resistance to water stress. The effect of elevated CO2 on the aperture of stomata, the level of nitric oxide( NO) in guard cells and the role of NO in CO2 elevation-induced stomatal closure in tomato ( Solanum lycocarpum L. ) were examined. In order to identify the enzymatic source of endogenous NO in guard cells, the role of nitric oxide synthase ( NOS ) and nitrate reductase ( NR ) in the CO2 elevation-induced NO accumulation was investigated. [Methods] Tomato( Solanum lycocarpum L. ) was used as experimental material.In E7/2 growth chambers, CO2 treatments and/or pharmacological experiment were initiated by treating stomata at a concentration of either 350 or 800 μL/L. Then, the stomatal aperture and NO level in guard cells were measured. The levels of NO in guard cells of tomato were determined using the cell NO-specific fluorescent probe. NO levels in guard cells were measured based on the intensity of fluorescence. NOS inhibitor L-NAME and NR inhibitor tungstate were used to assess the role of NOS and NR in the CO2 elevation-induced NO production, respectively.[Results] The present study showed that the stomatal aperture decreased to 2. 3 μm after 6 hours of elevated CO2 treatment, and decreased by 32% related to ambient CO2 treatment. The intensity of green fluorescence showed that the level of NO in guard cells were 88% higher under elevated CO2 than that under ambient CO2 . CO2 elevation-induced stomatal closure was reversed by treatment with NO scavenger cPTIO, the level of NO in guard cells decreased by 35% and the stomatal aperture increased to 3. 2μm, similar to those under ambient CO2 . Under elevated CO2 , addition of 200 μmol/L L-NAME increased the stomatal aperture by 30%, and decreased NO accumulation in guard cells by 33%; while addition of 100 μmol/L tungstate increased the stomatal aperture by 35% and NO accumulation in guard cells decreased by 40%. [Conclusions] Elevated CO2 significantly increased the level of NO in guard cells and decreased aperture of stomata compared to ambient CO2 . CO2 elevation-induced stomatal closure was reversed by scavenging NO, indicating that NO plays an important role in the induced stomatal closure of tomato by CO2 elevation. The pharmacological evidences showed that both NOS inhibitor L-NAME and NR inhibitor tungstate significantly decreased NO accumulation in guard cells and inhibited stomatal closure under elevated CO2 , suggested that both NOS and NR were involved in CO2 elevation-induced NO accumulation. Therefore, it seems to be concluded that elevated CO2 promotes the production of NO through both NOS and NR, and increases the level of NO in guard cells, and induces stomatal closure in tomato.