【正文】 NO處理對(duì)黃瓜幼苗生理生化的影響，為提高植物的抗鹽性提供一定的理論依據(jù)。鹽脅迫顯著降低了葉片葉綠素含量 ，顯著增加了可溶性糖含量，低濃度的NO處理增加葉片葉綠素含量，降低了可溶性糖含量，說明NO有利于黃瓜非光能的捕獲和轉(zhuǎn)化，明顯促進(jìn)植物的生長，降低鹽脅迫對(duì)黃瓜的抑制作用。關(guān)鍵詞：黃瓜，一氧化氮，低濃度，鹽脅迫，SNPEFFECTS OF SODIUM SNP ON SEEDINGS OF CUCUMBER UNDER NaCl STRESS ABSTRACTNitric oxide (NO) is an important active molecule in biology. It is now being evident that NO is also a ubiquitous signal molecule in plant kingdom. It was proved to participate in many key physiological , the effects of NO donor on the physiological and biochemical mechanisms in hydroponic cucumber seedlings under salt stress were investigated, in order to clarify the possible mechanisms of enhancing salttolerance in plants. Under the stress of 4g/Kg NaCl, the impact of SNP on the growth of cucumber seedlings were studied by substrate culture. The results showed that salt stress can restrain the growth of the cucumber under salinity stress, and reduce the content of soluble protein in cucumber leaves under salt stress ,improve the antioxidant enzymes GPX, the activity of CAT. It could be concluded that low concentration NO improves the oxidation resistance of cucumber leaf, reduced the membranous peroxidation damage induced by salt stress, NO may be involved in the metabolism, or physiological activity of plants. Salt stress significantly decreased leaf chlorophyll content, significantly increased the soluble sugar content, low concentration of NO treatment increase leaf chlorophyll content, reduced the content of soluble, shows NO benefit cucumber the capture and conversion of light energy, and obviously promote the growth of plants, reduce the inhibitory effect of salt stress on cucumber. In addition, the low concentration of SNP can alleviate salt stress on cucumber seedling morphological indicators such as plant height, stem diameter, leaf length width of inhibition. KEY WORDS: cucumber；nitric oxide；low concentration；salt stress；SNP 目 錄摘要Abstract1 前言 1 鹽分脅迫及SNP作用機(jī)理概述 1 2 鹽對(duì)種子萌發(fā)的影響 2 鹽對(duì)植物生長發(fā)育的影響 2 鹽對(duì)植物光合作用的影響 3 提高作物耐鹽性的途徑 3 培育耐鹽品種 3 利用鈣和微量元素 3 抗鹽鍛煉 4 植物激素調(diào)控 4 42材料和方法 5 供試材料及實(shí)驗(yàn)方法 5 生理指標(biāo)測定 5 葉綠素含量的測定 5 可溶性糖含量的測定 6 可溶性蛋白質(zhì)含量的測定 6 過氧化氫酶活性的測定 7 過氧化物酶活性的測定 7 形態(tài)指標(biāo)的測定 8 數(shù)據(jù)處理 83結(jié)果與分析 8 SNP對(duì)NaCl脅迫下黃瓜幼苗葉綠素含量的影響 8 SNP對(duì)NaCl脅迫下黃瓜幼苗可溶性糖含量的影響 9 12 SNP對(duì)NaCl脅迫下黃瓜幼苗形態(tài)指標(biāo)的影響 13 SNP對(duì)NaCl脅迫下黃瓜幼苗株高的影響 13 SNP對(duì)NaCl脅迫下黃瓜幼苗莖粗的影響 13 SNP對(duì)NaCl脅迫下黃瓜幼苗葉片數(shù)的影響 14 SNP 對(duì)NaCl脅迫下黃瓜幼苗葉長葉寬的影響 144結(jié)論與討論 15 15 15 SNP對(duì)NaCl脅迫下黃瓜幼苗的光合作用的影響 15 SNP對(duì)NaCl脅迫下黃瓜幼苗的可溶性糖和可溶性蛋白質(zhì)含量的影響。據(jù)統(tǒng)計(jì)全球約20%的耕地和半數(shù)可灌溉土地受到鹽漬化影響，目前我國約有600多萬公頃的次生鹽漬化土壤，約占百分之十的耕地面積，而且在以較快的速度在不斷擴(kuò)大和加劇[2]。鹽漬化是引起植物滲透脅迫及影響植物正常生長的主要原因之一，高鹽造成植物葉片氣孔關(guān)閉，降低植物光合作用效率。 鹽分脅迫及SNP作用機(jī)理概述土壤中鹽分過多對(duì)植物生長發(fā)育產(chǎn)生的危害叫鹽害。這種能力有著明顯的種間和種內(nèi)差異，植物在鹽漬環(huán)境中生長無法阻止鹽分進(jìn)入或排除鹽分，只能通過不同的生理途徑適應(yīng)或部分適應(yīng)使之不受傷害，維持正常生理活動(dòng)[5]。根據(jù)植物耐鹽能力的不同，可將植物大體上分為鹽生植物和淡土植物或非鹽植物。鹽生植物與淡土植物之間并沒有絕對(duì)的界限，往往相互交疊，而且不同植物種類和個(gè)體在不同發(fā)育階段對(duì)鹽分的反應(yīng)程度不同[6]。近年來，對(duì)NO植物學(xué)的研究表明，NO是具有生物活性和信號(hào)轉(zhuǎn)導(dǎo)作用的氣體活性分子,它不僅對(duì)植物的許多生命活動(dòng)如種子萌發(fā)，葉片伸展，生長發(fā)育和衰老等具有直接的生理調(diào)節(jié)功能,而且作為防御反應(yīng)中的關(guān)鍵信使,參與了植物對(duì)生物和非生物脅迫的響應(yīng)[7]，已經(jīng)有人把它作為一種新的植物激素，而硝普鈉SNP是外源一氧化氮的供體之一。另一方面，NO可以誘導(dǎo)植物系統(tǒng)性獲得抗性（SAR）的形成。NO能激活苯丙氨酸解氨酶PAL[8]。 鹽對(duì)種子萌發(fā)的影響種子能否在鹽脅迫下萌發(fā)形成苗，是植物在鹽堿條件下生長發(fā)育的