2000年 外文翻譯--通過(guò)5-氨基乙酰丙酸來(lái)改善棉苗的耐鹽性（節(jié)選）

1、<p>　　中文2635字,1634單詞，英文字符8440 </p><p>　　出處：Plant Growth Regulation 32: 99–103, 2000.</p><p>　　Improving salt tolerance of cotton seedlings with 5-aminolevulinic acid </p><p>　　

2、K.Watanabe1, T. Tanaka1, Y. Hotta1, H. Kuramochi2 & Y. Takeuchi2</p><p><b>　　ABSTRACT</b></p><p>　　Of 12 different plant growth regulators (PGRs) tested, 5-aminolevulinic acid (A

3、LA) was found to improve the salt tolerance of cotton seedlings. Cotton seedlings treated with ALA could grow in soil containing levels as high as 1.5% (wt/wt) NaCl. The analyses of mineral compositions of plant parts re

4、vealed that the Na+ concentrations in the roots of the plants treated with ALA were suppressed to low concentrations. From these results, it can be presumed that the presence of ALA may cause a reducti</p><p&g

5、t;　　Abbreviations: PGRs – plant growth regulators; ALA – 5-aminolevulinic acid hydrochloride; GA3 – gibberellin; BA – benzyladenine; IAA – indoleacetic acid; ABA – abscisic acid</p><p>　　Key words: 5-aminole

6、vulinic acid, cotton, Na+ uptake, plant growth regulators, salt-stress tolerance</p><p>　　Introduction</p><p>　　The salinization of soil has become an increasingly important topic. Because few c

7、rop plants can be grown successfully in saline soil where crop productivity is markedly low, saline land is rarely used as farmland. At the same time, the total area of arable land is gradu- ally decreasing due to the pr

8、ogressive salinization of soil [16]. The improvement of crop productivity in regions subjected to salt damage is a more serious and pressing challenge than ever for promoting desert greening and pre</p><p>　

9、　A number of studies are currently underway inwhich researchers are trying to cultivate plants in saline soil. For example, the possibility of imparting salt-stress tolerance to food crops such as rice and tobacco usi

10、ng genetic engineering and similar molecular-biological methods is under investigation [12, 15]. More research is needed before the knowl- edge gained can be used in practice.</p><p>　　Plant growth regulator

11、s (PGRs) are widely applied to agricultural crops as a means of crop improve- ment and often used to increase the stress resistance of plants. Despite the existence of several studies on improving salt tolerance using PG

12、Rs such as GA3 [1, 10, 14], none are used in practice.</p><p>　　In the present study, we evaluated 12 represen- tative PGRs and compared the effectiveness of each substance at improving the salt tolerance of

13、 cotton seedlings. We found that 5-aminolevulinic acid (ALA) was the most effective.</p><p>　　Materials and methods</p><p>　　Plant materials</p><p>　　For all experiments, cotton (M-

14、5 Acala) seeds were sown in plastic pots without drainage holes (surface area 450 cm2, 6,000 g of soil) and filled with soil to which 0.45 gN/pot of a compound fertilizer (N/P/K ratio 8:8:8) was applied as the dressing,

15、and grown in a greenhouse (15–25 ?C). At the cotyledon devel- oping phase, 5 seedlings of uniform size per pot were selected. Seedlings were treated by foliar spray with an aqueous solution of PGRs containing a wetting a

16、gent, Neoesterin (Kumiai Chem</p><p><b>　　Analyses</b></p><p>　　Plants were washed with distilled water, blotted dry, and weighed. They were divided into shoots and roots and placed

17、 in an oven at 80 ?C for 3 days, and then their dry weights were determined. For mineral determination, dried materials were ashed for 12 h at 550 ?C, and then an appropriate amount was digested in a mixture of hydrochlo

18、ric acid (1:1). The ion concentrations of Na+, K+, Mg2+, and Ca2+ were determined by an inductively coupled plasma spectrometry (ICP) analyzer (ICPS-2000, Shimadz</p><p>　　Results and discussion</p>&

19、lt;p>　　There are various studies with PGRs concerning the improvement of plant tolerance to salt, espe- cially regarding the effects of salt on growth. For example, several studies using GA3 have attempted to reduc

20、e NaCl-induced inhibition of growth. Agak- ishiev found that spraying the leaf surface of cotton plants with GA3 solution (concentration: 50 mg/l) caused a marked stimulation of growth despite a saline background [1]. St

21、arck reported that GA3 counter- acted the salt inhibition of growth, p</p><p>　　It has also been reported that cytokinin promotes seedling growth in bread wheat (Triticum aestivum Linn) under the influence o

22、f salinity [13] and prevents the salt-induced necrosis of tobacco leaves [2].</p><p>　　In examining uses of other PGRs, it has been suggested that presoaking seeds with IAA improved crop yield in a field tes

23、t under salt-stressed conditions [5], and ABA may have a role as a mediator in the effect of NaCl on plant physiological parameters [4].</p><p>　　We evaluated 12 representative PGRs using the results of a vi

24、sual observation on the 23rd day after the treatment. The growth of the cotton seedlings sprayed with the wetting agent-distilled water solution as a control was suppressed by the 0.5–1.0% NaCl in the soil, and the plant

25、s in the soil containing 1.5% NaCl died (Table 1). In the plants treated with ALA (concentration: 10–300 mg/l), a significant improve- ment in salt tolerance was seen, and these plants survived in the soil containing &

26、lt;/p><p>　　To determine how ALA application enhanced the salt resistance of cotton seedlings, the plants were harvested on the 3rd day after a 1.5% salt treatment and their weight was determined. The results a

27、re shown in Table 2 and Figure 1. Salinization withered the plants and caused ca. 50% reduction in both the fresh and total dry weight of the cotton. The ALA treatment significantly counteracted this reduc- tion, a

28、nd the weight of this group remained similar to that of the control group.</p><p>　　ALA is a key precursor in the biosynthesis of porphyrins such as chlorophyll and heme, and it was recently discovered that

29、at low concentrations ALA had a promotive effect on the growth and yield of several crops and vegetables [7, 8]. Also, ALA was effective in counteracting stress damage such as a lack of cold resistance in rice seedlings

30、[9]. In this study we have shown that cotton seedlings treated with ALA can grow in soil containing levels as high as 1.5% NaCl.</p><p>　　To clarify the adaptation mechanism of cotton seedlings to salt

31、stress promoted by ALA treatment, changes in the mineral compositions of plant parts were examined, including specially Na+ uptake in the roots and its transport from the roots to the shoots. The results showed that Na+

32、concentrations in the roots of the plants treated with ALA were the same as Na+ concentrations in the roots of plants that were not treated with salt (Figure 2). Although Na+ transport from the roots to the shoo</p>

33、;<p>　　It has been shown that cytokinin did not affect root salt-uptake but did cause a reduction in root-to- shoot transport [2]. As a result of these analyses, we conclude that ALA does not affect Na+ transport

34、from the roots to the shoots but that it might suppress the inflow of Na+.</p><p>　　Greenway and Munns summarized that plant responses to salt stress were distinguished by an adaptation towards no ion uptake

35、, rather than adaptation after absorbing ions, and this resulted in water deficiency and ion excess, respectively, if it could not be carefully controlled [6]. From these results, it can be presumed that the presence of

36、ALA may cause a reduction of Na+ uptake and may suppress water deficiency caused by osmotic stress resulting from high external Na+ concentrations. In order </p><p>　　Most importantly, it is generally known

37、that plants subjected to salt stress synthesize organic solutes such as glycine betaine, proline, and sugar alcohols for turgor maintenance [11]. As it has also been reported that ALA increases fructan (polyfructosylsuc

38、roses) content as nonstructural carbohydrate in rakkyo [18] and spinach [17] without salt stress, there is great interest in observing any relationship between these studies.</p><p>　　Our results suggest tha

39、t ALA at low concentrations (10–100 mg/l) has the potential to improve salt tolerance in cotton seedlings through foliar treatment. We hope ALA may be useful in helping to solve serious problems occurring on a global sca

40、le, such as the desertification of green lands and salt damage to farm lands.</p><p>　　通過(guò)5-氨基乙酰丙酸來(lái)改善棉苗的耐鹽性</p><p>　　K.Watanabe1, T. Tanaka1, Y. Hotta1, H. Kuramochi2 & Y.Takeuchi2</p>

41、<p><b>　　摘要</b></p><p>　　在測(cè)試了12種不同的植物生長(zhǎng)調(diào)節(jié)劑（PGRs）后發(fā)現(xiàn)5-氨基乙酰丙酸(ALA)可以提高棉苗的耐鹽性。用ALA處理過(guò)的棉苗可以在含有高達(dá)1.5%氯化鈉的土壤中生長(zhǎng)。對(duì)植物結(jié)構(gòu)礦物組合的分析表明用ALA處理過(guò)的植物根部鈉離子的濃度可被抑制。由此可推測(cè)ALA的存在可能會(huì)導(dǎo)致鈉離子的攝取。</p><p>　　

42、縮寫(xiě)形式：PGRs-植物生長(zhǎng)調(diào)節(jié)劑；ALA-5-氨基乙酰丙酸鹽酸鹽；GA3-赤霉素；BA-芐基腺嘌呤; IAA - 吲哚乙酸; ABA- 脫落酸</p><p>　　關(guān)鍵詞：5-氨基乙酰丙酸；棉花；鈉離子攝??；植物生長(zhǎng)調(diào)節(jié)劑；耐鹽性</p><p><b>　　1.引言</b></p><p>　　土壤鹽堿化已成為人們?nèi)找骊P(guān)注的話題。很少有作

43、物可以在鹽堿地里生長(zhǎng)，即使可以生長(zhǎng)，作物產(chǎn)量也很低，因此鹽堿地很少用作農(nóng)田。同時(shí)，由于日益嚴(yán)重的土壤鹽堿化使得耕地總面積逐漸減少[16]。提高遭受鹽堿侵害地區(qū)的作物產(chǎn)量是一項(xiàng)比以往任何時(shí)候都嚴(yán)肅和緊迫的挑戰(zhàn)，以此來(lái)促進(jìn)土地沙漠綠化并阻止土地沙漠化。</p><p>　　在目前進(jìn)行的大量研究中，研究者正試圖在鹽堿地里培育植物。例如，將植物耐鹽性用于水稻和煙草這樣的食品作物上。耐鹽性通過(guò)遺傳工程和類(lèi)似分子生物學(xué)的方法

44、來(lái)完成，這些方法仍在進(jìn)一步研究中[12, 15]。在這些知識(shí)用于實(shí)踐之前還需要更多的研究。</p><p>　　植物生長(zhǎng)調(diào)節(jié)劑(PGRs)可促進(jìn)作物生長(zhǎng)因此被廣泛地用在農(nóng)作物上，也經(jīng)常用于增加植物的抗性。盡管目前有許多關(guān)于使用像赤霉素[1, 10, 14]這樣的植物生長(zhǎng)調(diào)節(jié)劑來(lái)提升植物耐鹽性的研究，但沒(méi)有人在實(shí)踐中應(yīng)用。</p><p>　　在本研究中，我們?cè)u(píng)估了12種有代表性的植物生長(zhǎng)調(diào)

45、節(jié)劑，并對(duì)每種調(diào)節(jié)劑提高棉苗耐鹽性的有效性做了比較。結(jié)果發(fā)現(xiàn)5-氨基乙酰丙酸（ALA）是最有效的。</p><p><b>　　2.選材與方法</b></p><p><b>　　2.1植物物質(zhì)</b></p><p>　　在所有實(shí)驗(yàn)中棉苗（M-5 阿卡拉）種植在沒(méi)有排水孔（表面積為450平方厘米，6000克土壤）的塑料盆

46、中，盆中的土壤有0.45gN。盆中的化合肥料（氮：磷：鉀為8:8:8）作為敷料并在溫室里(15–25 ?C)生長(zhǎng)。在子葉發(fā)展階段每個(gè)花盆里5株大小均勻的植物被選出。Neoesterin（日本化學(xué)工業(yè)株式會(huì)社）用含有潤(rùn)濕劑的植物生長(zhǎng)調(diào)節(jié)劑噴灑幼苗葉面，使其稀釋2000倍。每一千平方千米的噴灑量為百升。所使用的濃度和植物生長(zhǎng)調(diào)節(jié)劑如下：10-300 ppm 的ALA（5-氨基乙酰丙酸）；0.03-1ppm的 GA3（赤霉素）；0.1-3pp

47、m的BA（芐基腺嘌呤）；0.3-10ppm的 IAA （吲哚乙酸）；1-30ppm的ABA（脫落酸）；0.1-3ppm的多效唑；0.3-10ppm的馬來(lái)酸酰肼膽堿鹽；0.1-3ppm的吲哚丁酸； 0.5-10 ppm的嘧啶醇； 0.3-10 ppm的乙烯利； 0.3-10 ppm的羥基異和0.3-10 ppm的N-二甲基天冬酰胺酸。經(jīng)過(guò)三天的處理 ，每克土壤Nacl重量從0%增長(zhǎng)至1,5%并溶于30ml水中，然后將其用液滴形式滴入花盆

48、中的土壤里。之后繼續(xù)</p><p><b>　　2.2分析</b></p><p>　　植株用蒸餾水洗滌、吸干并稱重。將它們分為芽和根并在80度的烘箱里放置三天，最終可測(cè)定它們的干重。在500度高溫的環(huán)境下干燥物料被灰化了因此可進(jìn)行礦物測(cè)定，然后取適量礦物材料置于鹽酸混合物中（1:1）。Na+, K+, Mg2+, 和Ca2+的離子濃度由感應(yīng)耦合等離子光譜（ICP）

49、分析儀（ICPS-2000,島津制作所）來(lái)測(cè)定[3]。</p><p><b>　　3.結(jié)果與討論</b></p><p>　　對(duì)可提高植物耐鹽性的植物生長(zhǎng)調(diào)節(jié)劑的研究做了許多，尤其是有關(guān)鹽分對(duì)植物生長(zhǎng)的研究。例如，應(yīng)用赤霉素的一些研究試圖降低氯化鈉誘發(fā)的生長(zhǎng)抑制素。Agakishiev發(fā)現(xiàn)植物雖有鹽分，但將赤霉素（濃度：50 mg/l）噴灑在棉花作物的葉面上會(huì)對(duì)植物

50、生長(zhǎng)有明顯的刺激[1]。Starck認(rèn)為赤霉素會(huì)抵消豆類(lèi)作物里鹽分的抑制生長(zhǎng)作用、光合作用和同化作用[14]。用赤霉素（濃度：100 mg/l）處理過(guò)的耐堿植物堿蓬可抵消生長(zhǎng)抑制，結(jié)果植物的干重有所增加。</p><p>　　受鹽堿的影響，細(xì)胞分裂素促進(jìn)小麥幼苗（小麥屬）生長(zhǎng)[13]并防止煙葉因鹽化而壞死。</p><p>　　研究其他植物生長(zhǎng)調(diào)節(jié)劑的用途時(shí)發(fā)現(xiàn)在鹽脅迫條件下用IAA浸泡過(guò)

51、的種子會(huì)使田地里產(chǎn)量增加[5]，ABA在Nacl對(duì)植物生理參數(shù)影響方面可能起著調(diào)節(jié)作用。</p><p>　　我們用處理后23天肉眼觀察到的結(jié)果來(lái)評(píng)估12種有代表性的植物生長(zhǎng)調(diào)節(jié)劑。在棉苗上噴灑濕潤(rùn)劑-蒸餾水溶液后，棉苗因在含有1.0% 氯化鈉的土壤里生長(zhǎng)而受到抑制，在含有1.5% 氯化鈉的土壤里死亡（表1）。用ALA（濃度：0–300 mg/l）處理過(guò)的植物在耐鹽方面有明顯提高，它們可以在含有1.5% 氯化鈉的

52、土壤里存活。然而這樣的效果并未在用其他植物生長(zhǎng)調(diào)節(jié)劑處理過(guò)的植物上體現(xiàn)出來(lái)（數(shù)據(jù)未顯示）。與前面提到的研究相比，在對(duì)棉苗的生物系統(tǒng)測(cè)定發(fā)現(xiàn)低濃度赤霉素溶液的使用并未產(chǎn)生明顯的效果。我們的結(jié)果也表明濃度超過(guò)1 mg/l的BA溶液處理會(huì)引起強(qiáng)烈的鹽害，還有，LAA和ABA溶液的處理不會(huì)影響棉苗的生長(zhǎng)。</p><p>　　為了確定ALA的使用是如何加強(qiáng)棉苗的耐鹽性，我們采用在含有1.5%的鹽分土壤里生長(zhǎng)了三天的植物并

53、確定它們的重量。表二和圖一的結(jié)果表明鹽堿會(huì)使植物枯萎并使棉苗的總干重減少50%。ALA的處理會(huì)明顯抵消這種降低作用，實(shí)驗(yàn)組的重量與控制組的重量保持一致。</p><p>　　ALA是卟啉（如葉綠素和血紅素）生物合成的關(guān)鍵前體。近來(lái)發(fā)現(xiàn)低濃度的ALA對(duì)幾種作物和蔬菜的生長(zhǎng)和產(chǎn)量由積極的促進(jìn)作用[7, 8]。此外，ALA還可有效抵消應(yīng)力損傷（如稻苗缺乏耐寒性）[9]。本研究表明用ALA處理過(guò)的棉苗可在含有高達(dá)1.5%

54、鹽分的土壤里生長(zhǎng)。</p><p>　　為了表明棉苗在ALA處理下耐鹽性提升的適應(yīng)機(jī)制，我們檢查了植物體礦物成分的變化，尤其是植物根對(duì)Na離子的攝取以及鈉離子從植物根部到植物地上部分的運(yùn)輸。結(jié)果表明用ALA處理過(guò)的植物根部鈉離子濃度與未處理過(guò)濃度相同（圖2）。雖然可觀察到ALA處理過(guò)的植物從根部到植物地上部分鈉離子的運(yùn)輸，但相比未經(jīng)過(guò)處理的鈉離子濃度，在1.5%的鹽分里植物地上部分的鈉離子濃度相對(duì)較低。在其它礦物

55、濃度方面沒(méi)有改變（表3）。</p><p>　　結(jié)果表明細(xì)胞分裂素并未影響植物根部鹽分的攝取，但卻引起植物根芽之間鈉離子運(yùn)輸?shù)慕档蚚2]。根據(jù)結(jié)果我們得出結(jié)論：ALA不影響植物從根部到地上部分鈉離子的運(yùn)輸，卻可能抑制鈉離子的流入。</p><p>　　Greenway 和 Munns認(rèn)為植物在面對(duì)鹽脅迫時(shí)不吸收離子，而不是吸收離子后再去適應(yīng)。如果不去適當(dāng)控制就會(huì)分別導(dǎo)致水分的缺乏和離子過(guò)量

56、的吸收[6]。從這些結(jié)果出發(fā)，我們推斷ALA的使用可能會(huì)減少鈉離子的攝取，也可補(bǔ)充水分的缺乏。水分的缺乏由外部高濃度鈉離子的滲透壓所引起。為更好地了解ALA提高耐鹽性的機(jī)制，我們還需進(jìn)一步的努力來(lái)確定細(xì)胞內(nèi)膜的滲透性和膨壓維持，以此來(lái)避免水分的缺乏。</p><p>　　最重要的是，植物為了適應(yīng)鹽分脅迫會(huì)合成有機(jī)溶質(zhì)，例如甘氨酸甜菜堿、脯氨酸和糖醇，來(lái)進(jìn)行膨壓維持[11]。研究也表明在無(wú)鹽脅迫條件下ALA會(huì)增加蕗