Immobilized zinc affinity chromatography of pectin hydroxamic acids for purification of trypsin inhibitors from soybean and sweet potato

Commercial pectin (with a 94% degree of esterification, DE94) suspended in methanol was reacted with methanolic alkaline hydroxylamine at room temperature for 20 h to prepare pectin hydroxamic acids (PHAs). The prepared PHA was coupled to the epoxy-activated Sepharose 6B gel to get immobilized PHA resins. The immobilized PHA resin was then balanced in column with 2 mM ZnCl2 in 50 mM Tris-HCl buffer (pH 7.9) to test the immobilized Zn-PHA gel as solid phase for immobilized metal affinity chromatography for the purification of trypsin inhibitors (TIs) from soybean and sweet potato. Using TI activity staining, it was found that purified TIs from the commercial soybean and sweet potato after trypsin affinity column purification could be adsorbed onto an immobilized Zn-PHA affinity column and eluted by 100 mM EDTA in 10 mM Tris-HCl buffer (pH 7.9). The immobilized Zn-PHA affinity column was used for TI purifications from crude extracts of sweet potato. The recovery of TI activity for one step was 90%, with 19.74-fold purification increase.     

Antioxidant activities of trypsin inhibitor, a 33 KDa root storage protein of sweet potato (Ipomoea batatas (L.) Lam cv. Tainong 57).

Trypsin inhibitors (TIs), root storage proteins, were purified from sweet potato (Ipomoea batatas[L.] Lam cv. Tainong 57) roots by trypsin affinity column according to the methods of Hou and Lin (Plant Sci. 1997, 126, 11-19 and Plant Sci. 1997, 128, 151-158). A single band of 33 kDa TI was obtained by preparative sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) gels. This purified 33 kDa TI had scavenging activity against 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical. There was positive correlation between scavenging effects against DPPH (2 to 22%) and amounts of 33 kDa TI (1.92 to 46 pmol). The scavenging activities of 33 kDa TI against DPPH were calculated from linear regression to be about one-third of those of glutathione between 5 and 80 pmol. Using electron paramagnetic resonance (EPR) spectrometry for hydroxyl radical detection, it was found that 33 kDa TI could capture hydroxyl radical, and the intensities of EPR signal were significantly decreased from 1.5 to 6 pmol of 33 kDa TI compared to those of the controls. It is suggested that 33 kDa TI, one of the sweet potato root storage proteins, may play a role as an antioxidant in roots and may be beneficial to health when it is consumed.     

Identification of a Kunitz-type proteinase inhibitor from Pithecellobium dumosum seeds with insecticidal properties and double activity

A trypsin inhibitor, PdKI, was purified from Pithecellobium dumosum seeds by TCA precipitation, trypsin-sepharose chromatography, and reversed-phase-HPLC. PdKI was purified 217.6-fold and recovered 4.7%. SDS-PAGE showed that PdKI is a single polypeptide chain of 18.9 kDa and 19.7 kDa by MALDI-TOF. The inhibition on trypsin was stable in the pH range 2-10 and at a temperature of 50 degrees C. The Ki values were 3.56 x 10(-8)and 7.61 x 10(-7) M with competitive and noncompetitive inhibition mechanisms for trypsin and papain, respectively. The N-terminal sequence identified with members of Kunitz-type inhibitors from the Mimosoideae and Caesalpinoideae subfamilies. PdKI was effective against digestive proteinase from Zabrotes subfasciatus, Ceratitis capitata, Plodia interpunctella, Alabama argillaceae, and Callosobruchus maculatus, with 69, 66, 44, 38, and 29% inhibition, respectively. Results support that PdKI is a member of the Kunitz inhibitor family and its insecticidal properties indicate a potent insect antifeedant.     

Chemical changes induced by methyl jasmonate in oilseed rape grown in the laboratory and in the field

The effect of methyl jasmonate (MJ) spraying on the chemistry of Brassica plants was investigated. Glucosinolates (GLS) in the leaves, stems, and roots of laboratory-grown oilseed rape (Brassica rapa subsp. oleifera cv. Tuli and Valo) 3 and 7 days after MJ treatment were analyzed. Volatile organic compounds (VOCs) from whole oilseed rape plants were collected 3 days after MJ treatment. GLS were also analyzed from field-grown oilseed rape (cv. Valo) treated with MJ. The production of indolyl GLS in laboratory-grown oilseed rape, especially the concentration of 4-hydroxy-3-indolylmethyl (4-OH-glucobrassicin) in leaves, stems, and roots, 3-indolylmethyl (glucobrassicin) in stems, and 4-methoxy-3-indolylmethyl (4-methoxyglucobrassicin) in roots, was induced after MJ treatment. The VOC emission profile changed after MJ treatment, and homoterpene (E)-4,8-dimethyl-1,3,7-nonatriene (DMNT) was detected only in MJ-treated plants. The GLS concentration in the field-grown plants was significantly higher in MJ-treated plants than in control plants. These results suggest that spraying with MJ induces the production of secondary compounds, that is, GLS and VOCs, in Brassica plants. The induction of VOC emissions in oilseed rape is comparable to that caused by insect feeding damage. Thus, MJ-treated crop plants may become less palatable to insect herbivores and more attractive to natural enemies of herbivores.     

Relative abundance and inhibitory distribution of protease inhibitors in potato juice from cv. Elkana.

Protease inhibitors from potato juice of cv. Elkana were purified and quantified. The protease inhibitors represent ca. 50% of the total soluble proteins in potato juice. The protease inhibitors were classified into seven different families: potato inhibitor I (PI-1), potato inhibitor II (PI-2), potato cysteine protease inhibitor (PCPI), potato aspartate protease inhibitor (PAPI), potato Kunitz-type protease inhibitor (PKPI), potato carboxypeptidase inhibitor (PCI), and "other serine protease inhibitors". The most abundant families were the PI-2 and PCPI families, representing 22 and 12% of all proteins in potato juice, respectively. Potato protease inhibitors show a broad spectrum of enzyme inhibition. All the families (except PCI) inhibited trypsin and/or chymotrypsin. PI-2 isoforms exhibit 82 and 50% of the total trypsin and chymotrypsin inhibiting activity, respectively. A strong variation within the latter activities was shown within one family and between protease inhibitor families.     

水稻叶色突变对虫害发生的影响研究初报

为明确叶色标记水稻在生产中可能引起的虫害发生的变化,本试验在使用和不使用农药防治的情况下,以常规品种嘉禾218为对照,对龙特甫B及其2个叶色突变系黄玉B、翠玉B田间虫害情况进行了调查。龙特甫B为正常绿叶籼稻品种,黄玉B、翠玉B全生育期分别表现黄色和翠绿色,在苗期、分蘖期和抽穗期,黄玉B较龙特甫B的叶绿素含量分别下降58.0%, 48.4%和40.8%,翠玉B则分别下降39.5%,36.0%和29.5%。结果表明,秧田期2个叶色突变体上的稻蓟马虫量显著高于其亲本龙特甫B;本田中灰飞虱和褐飞虱的虫口数在不同材料间或差异不显著,或存在显著差异,但没有一定的规律性。但是,2个突变体受稻纵卷叶螟的危害显著轻于龙特甫B,表现为盛发期突变体受稻纵卷叶螟危害产生的虫苞数显著少于龙特甫B,而龙特甫B与嘉禾218之间没有显著差异;相反,2个突变体植株上白背飞虱的虫量显著大于龙特甫B,龙特甫B也显著大于嘉禾218。根据植株的农艺性状和叶绿素含量,以及虫害发生动态变化,笔者推测,造成叶色标记水稻稻纵卷叶螟危害变轻的原因可能与植株叶绿素含量下降,影响幼虫生长发育有关,但引起白背飞虱虫口增加的原因尚需进一步研究。本试验为首次对叶色标记水稻虫害发生情况进行研究,所得结果不但对完善叶色标记水稻生产体系具有指导意义,同时对研究害虫与水稻叶色之间的关系也具有理论价值。     

水稻叶色突变对虫害发生影响的研究初报

为明确叶色标记水稻在生产中可能引起的虫害发生变化,本试验在使用和不使用农药防治的情况下,以常规品种嘉禾218为对照,对龙特甫B及其2个叶色突变系黄玉B、翠玉B田间虫害情况进行了调查.龙特甫B为正常绿叶籼稻品种,黄玉B、翠玉B全生育期分别表现黄色和翠绿色,在苗期、分蘖期和抽穗期,黄玉B较龙特甫B的叶绿素含量分别下降58.O%,48.4%和40.8%,翠玉B则分别下降39.5%,36.0%和29.5%.结果表明,秧田期2个叶色突变体上的稻蓟马虫量显著高于其亲本龙特甫B;本田期灰飞虱和褐飞虱的虫口数在不同材料间或差异不显著,或存在显著差异,但没有一定的规律性.但是,2个突变体受稻纵卷叶螟的危害显著轻于龙特甫B,表现为盛发期突变体受稻纵卷叶螟危害产生的虫苞数显著少于龙特甫B,而龙特甫B与嘉禾218之间没有显著差异;相反,2个突变体植株上白背飞虱的虫量显著大于龙特甫B,龙特甫B也显著大于嘉禾218.根据植株的农艺性状和叶绿素含量,以及虫害发生动态变化,笔者推测,造成叶色标记水稻稻纵卷叶螟危害变轻的原因可能与植株叶绿素含量下降,影响幼虫生长发育有关,但引起白背飞虱虫口增加的原因尚需进一步研究.本试验为首次对叶色标记水稻虫害发生情况进行研究,所得结果不但对完善叶色标记水稻生产体系具有指导意义,同时对研究害虫与水稻叶色之间的关系也具有理论价值.     

火龙果种子清蛋白的理化性质及其胰蛋白酶抑制活性研究

为阐明火龙果种子清蛋白的理化性质和生物学活性,本研究从红心火龙果中纯化获得种子清蛋白(HPA),分析其分子量、氨基酸组成、同源性及胰蛋白酶抑制活性。结果表明,HPA由两条分子量为12.6、13.2 kDa的多肽链(HPA-1,HPA-2)组成。 HPA富含谷氨酸(6.297 g·100g^-1)、精氨酸(3.992 g·100g^-1) 和天冬氨酸(2.694 g·100g^-1)。 HPA与来自甜菜和菠菜2S种子贮藏蛋白具有高度相似性。HPA-2显示出较高的胰蛋白酶抑制活性,比活力为9.19×10³ TIU· mg^-1,纯化倍数为1.86。经大豆胰蛋白酶抑制剂-琼脂糖凝胶柱纯化的组分HPA-2-1是胰蛋白酶竞争性抑制剂,抑制常数(Ki)为0.62 nmol·L^-1, 具有Kunitz型抑制剂的摩尔比曲线。 HPA-2-1在一定的pH值(2~10)和温度(30~70℃)范围内具有稳定的抑制活性,且抑制活性几乎不受二硫苏糖醇(DTT)的影响。本研究为挖掘火龙果种子资源,丰富胰蛋白酶抑制剂的种类提供了参考。     

Influence of Potassium Substitution by Rubidium and Sodium on Growth,Ion Accumulation,and Ion Partitioning in Bean under High Alkalinity

ABSTRACT

The effects of partial and complete substitution of potassium (K⁺) by rubidium (Rb⁺) and sodium (Na⁺) on plant growth and ion accumulation and partitioning was studied in bean young plants cultivated in nutrient solution with or without bicarbonate (HCO₃ ^?)-induced alkalinity. Plant growth was significantly decreased due to alkalinity and the substitution of K⁺, being leaves more affected than roots. Rubidium caused a severe toxicity reflected in a reduction in root dry mass and total chlorophyll concentration. Ion partitioning was markedly altered by alkalinity. Content of nitrogen (N), calcium (Ca), magnesium (Mg), iron (Fe), K, and Na were more accumulated in the roots in HCO₃ ^?-treated plants, while decreased in the shoot. Iron (Fe) was accumulated at similar extent in plants with and without high alkalinity, except in plants grown in Rb⁺ solutions. However, Fe was more accumulated in the roots, suggesting that chlorophyll synthesis was impaired by reduced translocation or internal inactivation of Fe. Zinc total uptake was severely reduced under high alkalinity in plants grown in Na⁺ solutions, maybe due to decreased Zn activity. Calcium was translocated more actively to the leaves and Mg was accumulated more in the roots of plants in Na⁺solutions. Despite the severe decrease in plant dry mass caused by Rb⁺, there was a higher translocation of N, phosphorus (P), Ca, Mg, Fe, zinc (Zn), copper (Cu), and manganese (Mn) from the roots to the leaves.     

Investigating the influence of transgenic tobacco plants codifying a protease inhibitor on soil microbial community

Serine protease inhibitors (PIs) are involved in several physiological processes, such as regulation of endogenous proteinases and defence against phytophageous insects. Transgenic modifications have enhanced protease inhibitor expression to develop insect resistant cultivars in several important crops. The fate of protease inhibitors released from genetically engineered plants is an important issue because of possible inhibition of soil proteases and effects of the insecticidal protein and its codifying sequence on soil microorganisms. The persistence of transgenic sequence mustard trypsin inhibitor-2 in soil and its hypothetical acquisition by soil microorganisms by horizontal gene transfer and the effect of transgenic plant material on soil microbial community structure and soil protease activity were investigated. With the aim to simulate the effects of plant litter on soil microorganisms, a microcosm experimental model was used. Despite the persistence of transgenic DNA sequences, no recombination event was detected between plant DNA and soil bacteria; molecular analysis of bacterial community also showed no significant influence on the dominant members of the bacterial community and soil protease activity was not inhibited by the release of constitutively over-expressed protease inhibitor.     

Insect resistance of a full sib family of tetraploid switchgrass Panicum virgatum L. with varying lignin levels

Little information is available on insect resistance mechanisms and inheritance in biomass grasses. Although reduction of lignin in biomass grasses in order to increase the efficiency of fermentation may result in increased susceptibility to insect feeding, other resistance mechanisms may be more important. Field grown leaves of two tetraploid parent (Kanlow N1, Summer) and 14 progeny switchgrass (Panicum virgatum L.) plant clones selected for a diversity of plant form and ranges in lignin levels were tested for leaf resistance to feeding by the fall armyworm (Spodoptera frugiperda J. E. Smith), a grass feeding insect pest. Although lignin generally appeared important as a resistance mechanism only at early season stages, replicate clones of two low lignin progeny plants generally remained resistant to fall armyworm feeding. Mechanical damaging increased resistance to fall armyworm feeding in several of these plants. Degrees of resistance were sometimes associated with leaf form of progeny. These results indicate there are likely multiple insect resistance mechanisms operating at different stages in switchgrass, and that segregation of some mechanisms appears related to growth form of the plants.     

Invertase inhibitors from sweet potato (Ipomoea batatas): purification and biochemical characterization

Two proteinaceous invertase inhibitors, designated ITI-L and ITI-R, were purified to electrophoretic homogeneity. ITI-L was purified from acetone powder of sweet potato leaves through sequential steps entailing buffer extraction, acid treatment, DEAE-Sephacel ion-exchange chromatography, and Sephacryl S-100 gel filtration. ITI-R was purified from sweet potato tuberous roots by sequentially applying buffer extraction, Con A-Sepharose affinity chromatography, DEAE-Sephacel ion-exchange chromatography, Sephacryl S-200, and Superose 12 gel filtration. The optimal pHs for interaction between ITI-L and ITI-R and acid invertase from sweet potato leaves were 5.5 and 5.0, respectively. The molecular masses of ITI-L and ITI-R were 10 and 22 kDa, respectively, as estimated by both gel filtration and SDS-PAGE. Both inhibitors were thermostable (90% of the activity remained after incubation at 100 degrees C for 20 min), and Western blotting showed them to be immunologically related.     

Effects of Broomrape Parasitism on Sunflower Plants: Growth,Development, and Mineral Nutrition

Sunflower broomrape (Orobanche cumana Wallr.) is a parasitic plant that infects sunflower (Helianthus annuus L.) plants. In this work, sunflower plants were grown under greenhouse conditions in pots with the substrate infested or non-infested with broomrape seeds. At different numbers of days after sowing, plant height, internode lengths, number of leaves, head diameter, mineral composition of leaves, and potassium (K) concentration in stem were measured. The negative effects of broomrape parasitism were assessed from 57 d after sowing, when broomrape started to emerge. Parasitized plants exhibited lower shoot dry weight, height, and head diameter than control plants. The reduction in internode lengths was associated with a decrease in the gradient of K concentration from basal to apical stem. The mineral composition of leaves was also affected in parasitized plants. The concentrations of calcium (Ca), magnesium (Mg), manganese (Mn), and zinc (Zn) in leaves of parasitized plants were lower than those of the control plants, while there were few differences for K, phosphorus (P), iron (Fe), and copper (Cu). The effects of parasitism are discussed in relation to their competition for resources and to perturbations of the host physiology such as hormonal and water balance.     

Content of boron and other elements in main stem and branch leaves and seed of soybean

Tissue testing is commonly used to determine nutrient status of crops, however, there may be differences in macro‐ and micronutrient content of main stem and branch leaves of plants. Macro‐ and micronutrient analyses of main stem and branch soybean (Glycine max [L] Merr.) leaves were performed separately to ascertain where foliar‐applied boron (B) was accumulating and to determine if other nutrients were partitioned differently between main stem and branch leaves in control plants and plants treated with foliar B. Foliar applications of 2.24 kg B/ha increased main stem leaf B content from 47 to 248 μg/g and caused leaf manganese (Mn) and aluminum (Al) content to decline. In a separate experiment, foliar applications of 1.12 kg B/ha onto soybean growing on a soil high in available Al increased B leaf content by over 50 μg/g and decreased leaf Al content by 100 μg/g. In other field experiments, foliar B applications of 0.90 kg/ha or more increased leaf B content in both main stem and branch leaves. Boron content was consistently higher in branch leaves than in main stem leaves. Branch leaves and seeds of soybean were higher in the phloem‐mobile elements potassium (K), magnesium (Mg), phosphorus (P), zinc (Zn), iron (Fe), and copper (Cu) than main stem leaves. With the exception of B, the relatively phloem‐immobile elements, calcium (Ca) and Mn were lower in branch leaves than in main stem leaves. The higher B content in branch leaves and seeds may indicate that B is more mobile in soybean than previously thought. The difference in macro‐ and micronutrient content of branch and main stem leaves and seeds should be noted when soybean leaves are being harvested for determination of macro‐ and micronutrient sufficiency, or when seeds are harvested for nutrient quality determinations.     

烟粉虱取食对不同抗虫性辣椒品种营养物质和抗性物质的影响

为了探讨烟粉虱取食对辣椒体内营养物质和抗性物质的影响,选择抗虫辣椒品种(‘新一代三鹰椒’、‘新苏椒五号’)和感虫品种(‘苏椒13号’、‘苏椒15号’)各2个,每株辣椒分别接烟粉虱成虫0头(对照)、30头(低密度)、60头(中密度)和120头(高密度),取食24 h后测定辣椒叶片中叶绿素、可溶性糖、可溶性蛋白以及酚类、黄酮类化合物含量。结果发现,低密度的烟粉虱取食后,辣椒叶片叶绿素含量显著上升,随着虫口密度的提高,叶绿素含量有所下降,但仍高于对照;感虫辣椒品种的叶绿素含量增加幅度高于抗虫品种。低密度和高密度的烟粉虱取食后,辣椒叶片中可溶性糖含量出现明显下降趋势,抗虫品种的下降幅度大于感虫品种。低密度和中密度的烟粉虱取食后,辣椒叶片中可溶性蛋白含量显著下降,但高密度烟粉虱取食后辣椒叶片中可溶性蛋白含量明显上升;抗虫品种的变化幅度明显高于感虫品种。烟粉虱取食后,叶片中酚类化合物含量明显上升,感虫品种的上升幅度较抗虫品种上升幅度大;随着虫量的增加,辣椒叶片中酚类化合物含量呈明显上升趋势,但高密度烟粉虱取食后酚类化合物含量出现明显下降趋势。烟粉虱取食后,感虫辣椒品种‘苏椒15号’叶片中黄酮类化合物含量明显上升;其他3个品种在中等以下密度的烟粉虱取食时,黄酮类化合物与对照差异不显著,但在高密度烟粉虱取食时,黄酮类化合物明显高于对照。研究表明,烟粉虱取食可引起辣椒营养物质和抗性物质含量向着有利于提高抗虫性的方向改变,但不同虫口密度下不同辣椒品种的改变幅度不同。研究结果为进一步揭示寄主植物与烟粉虱之间的防御和反防御机制提供了基础。     

cDNA clone of a putative peanut (Arachis hypogaea L.) trypsin inhibitor has homology with peanut allergens Ara h 3 and Ara h 4

Trypsin inhibitors are pathogenesis-related (PR) proteins, which play an important role in the plant defense mechanism against insects and pathogens. Peanut trypsin inhibitors are low molecular mass seed storage proteins. Like peanut allergens, they are stable to acid and heat, resistant to digestion, and can have a negative impact on human health. In peanut, five Bowman-Birk trypsin inhibitors (BBTI) have been isolated and amino acid sequences published. However, to date, no peanut BBTI sequence is available at both the cDNA and the genomic levels. The objectives of this investigation were (i) to synthesize degenerate oligonucleotides based on conserved regions of published amino acid sequences of BBTI, BII, and BIII; (ii) to isolate, sequence, and analyze at least one positive peanut trypsin inhibitor cDNA clone using the synthesized (32)P-labeled oligonucleotides as probes; and (iii) to determine its trypsin inhibitory activity. Thirty-two degenerate oligonucleotides DNA primers of 24 nucleotides each were synthesized based on the published amino acid sequences of peanut BBTI, and two were selected as probes to screen a peanut Lambda gt 11 cDNA library. Three putative positive clones were isolated, purified, and subcloned, and one was sequenced. Sequence analysis revealed a partial cDNA clone of 643 bp with a start codon. This clone shares 93 and 96% nucleotide sequence homology with peanut allergens Ara h 3 and Ara h 4 cDNA clones, respectively. A trypsin inhibitor assay revealed that peanut allergen Ara h 3 has a trypsin inhibitory activity of 11 238 TIA/mg protein. We concluded that peanut allergen Ara h 3 may also function as a trypsin inhibitor.     

Mung bean trypsin inhibitor is effective in suppressing the degradation of myofibrillar proteins in the skeletal muscle of blue scad (Decapterus maruadsi)

Mung bean trypsin inhibitor (MBTI) of the Bowman-Birk family was purified to homogeneity with a molecular mass of approximately 9 kDa on tricine-sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and 8887.25 Da as determined by matrix-assisted laser desorption/ionization-quadrupole ion trap-time-of-flight mass spectrometry (MALDI-QIT-TOF MS). Using blue scad myofibrillar proteins as targets, it was found that, in the absence of MBTI, proteolysis of myofibrillar proteins, especially myosin heavy chain (MHC), could be identified after incubation at 55 °C for 2 h, while in the presence of MBTI, with a final concentration of 25 ng/mL, proteolysis of these proteins was greatly suppressed even after incubation for 3 h. Although cysteine proteinase inhibitor E-64 was also effective in preventing protein degradation, inhibitors for metallo- and asparatic proteinases did not reveal obvious inhibitory effects. Our present results strongly suggested that the naturally occurring legume bean seed protein MBTI can be used as an effective additive in preventing marine fish blue scad surimi gel softening, which is quite possibly caused by myofibril-bound serine proteinase (MBSP).     

Glycolic acid oxidase activity in crop plant leaves

Many workers have revealed the possible role of glycolic acid oxidase in the photosynthesis and the respiration of plant leaves (1, 5) and in the organic acid metabolism of rice plant roots (6). There is also abundant evidence that α-hydroxysulfonates, the bisulfite addition compounds of aldehydes and ketones, are the specific and competitive inhibitors of the enzyme (7, 8). The pevious works (9, 10) showed that a deficient application of potassium increased the content of amino-N and reducing sugars and concomitantly the respiratory activity in sweet potato roots. Such a derangement in the metabolic status of plant roots would be expected to be intimately connected with any changes in the photosynthesis and the respiration of the leaves. This paper, as a preliminary, describes some results from investigations into the glycolic acid oxidase activity in leaves of rice plant- and barley seedlings, sweet potato plants, and taro plants which were grown in solution culture at varying potassium application : the effects of light and plant age on enzyme activity, the activation of the enzyme by FMN addition, the stability of the enzyme during a prolonged incubation of sap from leaves, and the inhibitory effects of specific inhibitors on the enzyme in vitro and in vivo.     

缺镁对菜豆幼苗膜脂过氧化及体内活性氧清除酶系统的影响

营养液中培养菜豆幼苗,缺镁菜豆植株生长受抑,生物量显著低于正常供应镁的植株,体内镁浓度和镁的积累总量均较低。严重缺镁黄化叶片中叶绿素含量下降。完整叶绿体的希尔反应值在缺镁与正常植株间无差别。缺镁菜豆植株的根和叶膜造性（以相对电导率表示）增加,叶片中丙二醛含量升高。活性氧清除酶系统:SOD、POD、CAT活性在缺镁菜豆真叶中高于正常植株,老叶中抗坏血醒过氧化物酶（AsA-POD）活性增加程度也较大。