Effect of maleic hydrazide on peroxidase isoenzymes in relation to rooting hypocotyl cuttings ofPhaseolus mungo

A time course study of changes in the pattern of peroxidase isoenzymes shows that two new isoenzymesa andb appeared in hypocotyl cuttings cultured either in indolyl-3 acetic acid (IAA) + sucrose or in water but not in maleic hydrazide (MH). Roots were also initiated in the former two cases but not in the last case. That these isoenzymes may be associated with root initiation is also evident from the fact that these appeared when hypocotyl cuttings were transferred from MH to IAA + sucrose. The time of appearance of these isoenzymes in different cultures also synchronized with the time of microscopic root initiation. While the isoenzymea disappeared,b persisted in cuttings transferred from IAA + sucrose to MH. The number of roots produced on cuttings transferred to MH was very low, though their development was normal. It is suggested that isoenzymesa andb may be associated with root initiation andc andd with root development.     

Ethylene effects on peroxidases and cell growth patterns in Picea abies hypocotyl cuttings

The effect of 2-chloroethylphosphonic acid (ethrel) on cell growth patterns and per-oxidase activity (EC 1.11.1.7) and location in young Norway spruce cuttings ( Picea abies [L.] Karst.) was investigated. The peroxidase activity in a fraction containing soluble and membrane bound enzymes show a diurnal variation, with decreased activity during the light period and a corresponding increase during the following dark period. The decrease during the day could to some extent be counteracted by treatment with ethrel. It appears that ethrel affects only peroxidases in the isolated membrane fraction, since peroxidases bound to the cell wall were not affected by ethrel. In vitro experiments indicated that the hydrophobicity of soluble peroxidases was increased by treatment with ethylene. Cytochemical localization of peroxidase activity in differentiating tracheids revealed a clear ethrel-induced increase in the tonoplast. It appears that ethylene affects soluble peroxidases in vivo in such a way that they are directed to a more hydrophobic environment, like the tonoplast. Treatment with ethrel also changed the appearance of the rough endoplasmic reticulum (ER) and Golgi apparatus. Dilated ER cisternae were observed on electron micrographs, as a result of treatment with ethrel. The number of vesicles produced by the Golgi apparatus and also the amount of vesicles fusing with the plasma membrane in secondary-wall-forming tracheids increased considerably. The results clearly indicate that the stimulatory effect of ethylene in spruce seedlings on lignification and cell wall formation, is due to a general stimulation on both synthesis, transport and secretion of cell wall material and not on a stimulation of peroxidase activity as reported for other species.     

Changes in peroxidase isoenzymes of Phaseolus mungo hypocotyl cuttings during rooting

A time course study of changes in the pattern of peroxidase isoenzymes shows that two new isoenzymes a and b appeared in hypocotyl cuttings in     

Ethylene accelerates the breakdown of cytokinins and thereby stimulates rooting in Norway spruce hypocotyl cuttings

Cuttings were taken from 4-week-old seedlings of Norway spruce ( Picea abies L. Karst.) raised at two different irradiation levels. Rooting experiments showed that root formation was increased by the ethylene formed by adding 1-aminocyclopropane-1-carboxylic acid ACC or Ethrel, especially in the slowly rooting cuttings grown under high light (HL). Cobaltousion. an ethylene synthesis inhibitor, delayed rooting, especially in the easily rooted cuttings grown under low light (LL).
Compounds isolated from the cuttings using immunoaffinity chromatography, on a column with antibodies against cytokinins, and separated by HPLC decreased in amount during the first week of the rooting period. An increase in ethylene production accelerated this process, especially in cuttings grown under HL, whereas cobaltous ion delayed it. We suggest that ethylene stimulates rooting by enhancing the degradation of cytokinins.     

Effect of some benzyl alcohols on rooting of bean cuttings

The root differentiating properties of various benzyl alcohols were studied using a bean rooting test. The results showed that the methoxy derivatives enhanced rooting more efficiently than did the hydroxy derivatives. Only 4-hydroxybenzyl alcohol inhibited rooting, but the addition of IAA at 10^?5M nullified the inhibition. Root promotion by the alcohols with a hydroxy group in the o-or p-position was increased by the addition of IAA. Auxin did not modify the rooting stimulation caused by the methoxy derivatives. The position of the methoxy group did not influence the rooting activity.     

Promotion of rooting in mung bean hypocotyl cuttings with ethrel, an ethylene releasing compound

Ethrel increased the number of roots on mung bean hypocotylcuttings under continuous illumination but decreased their length.IAA, GA₃) kinetin and TIBA inhibited both the number and length.Inhibitory effect of GA3 and kinetin on root number was overcomeby ethrel but on root length was enhanced. Ethrel in combinationwith IAA promoted the number and length of roots synergisticallybut enhanced the inhibitory effect of TIBA on both. (Received June 27, 1970; )     

Synergistic effect of ribose and 2-deoxy-ribose with nutrition and auxin in rooting hypocotyl cuttings of Phaseolus mungo

Exogenously supplied ribose and deoxyribose in a medium containingsucrose+ IAA considerably enhanced the formation of roots onhypocotyl cuttings of Phaseolus mungo with intact apex andleaves.The effect increased with increasing concentration of pentosesugars and was more pronounced with deoxyribose than with ribosesugar. (Received October 25, 1975; )     

Photoperiodic studies on growth and development of Impatiens balsamina L.

Summary Seedlings of Impatiens balsamina raised under ND and LD conditions were divided into two sub-groups each when they had reached 5-leaf stage. While one sub-group was left under the same condition (NDND or LDLD), the other was transferred to the other photoperiod (NDLD or LDND). NDND plants were subdivided into 2 lots. One of these was transferred to SD in May. The dates of emergence of individual branches and floral buds were recorded and the vegetative period was calculated in each case.It was found that in NDND plants floral buds were produced from all the nodes except the lowermost which produced a single vegetative branch. In LDND plants the vegetative branches were produced from the lower 9 nodes but floral buds from those above these. Small leafy structures which ultimately dried up were produced from a few top nodes in both these cases. In contrast to this in LDLD plants only vegetative branches were produced from all the nodes. In NDLD plants floral buds were produced from the lower 3–5 nodes prior to transfer to LD condition, but vegetative branches were produced from the upper nodes after this transfer. Even some of the lower floral buds reverted to vegetative state under this condition.The production of floral buds or the vegetative branches as the case may be, occurred in acropetal succession under all the photoperiodic conditions and never in basipetal manner.LDLD and NDLD plants, which did not flower at all, continued to produce lateral branches without showing any sign of senescence, while LDND and NDND ones showed yellowing of the apical growing point which spread downwards and lead ultimately to the death of the plant. The senescence was hastened when these plants were transferred to SD condition towards the end of May. The senescence therefore, appears to be related with reproductive development. The results are discussed in the light of current literature.     

Photoperiodic studies on growth and development of Impatiens balsamina L.

Summary In the short-day plant Impatiens balsamina it was found that, while floral buds are initiated with 3 short-day (SD) cycles, at least 8 such cycles are required for flowering. The numbers of floral buds and open flowers bear a linear relationship with the number of SD cycles. The induced floral buds revert to vegetative growth unless the plants receive the minimum number of SD cycles needed for flowering, this reversion occurring in a basipetal direction. The rate of extension growth of the stem increases with increasing numbers of SD cycles. The high rate is maintained longer in plants receiving 32 or more SD cycles, but the subsequent fall is also steeper in these plants than in plants receiving less inductive cycles. Senescence also occurs in these plants and appears to be related to the magnitude of reproductive development and the high rate of extension growth.     

Effect of cycloheximide on GA3 response and on photoperiodic reactions of Impatiens balsamina L.

GA₃ increased the extension growth of Impatiens balsamina L.till 56 days under 8- and 24-h photoperiods. Cycloheximide whichdecreased height slightly under inductive conditions at a laterstage did not affect the GA₃-promoted extension growth. BothGA₃ and cycloheximide caused enhancement of the rate of differentiation,although this effect was temporary in the case of GA₂. Cycloheximidedoes not affect photoperiodic induction, whereas it hastensand increases the magnitude of GA₂-induced flowering.     

Activity and isoforms of peroxidases, lignin and anatomy, during adventitious rooting in cuttings of Ebenus cretica L

Adventitious rooting of Ebenus cretica cuttings was studied in order to examine a) the rooting ability of different genotypes in relation to electrophoretic patterns of peroxidases. b) the activity and electrophoretic patterns of soluble and wall ionically bound peroxidases, the lignin content and anatomical changes in the control and IBA treated cuttings of and genotypes in the course of adventitious root formation. In addition, a fraction of soluble cationic peroxidases was separated by gel filtration chromatography from the total soluble peroxidases of a genotype. No rooting occurred in cuttings without IBA-treatment. In both genotypes, electrophoretic patterns of soluble anionic peroxidases revealed two common peroxidase isoforms, while a fast-migrating anionic peroxidase isoform (A3) appeared only in genotypes. Both genotypes showed similar patterns of soluble, as well as wall ionically bound cationic peroxidase isoforms. The number of isoforms was unchanged during the rooting process (induction, initiation and expression phase) but an increase in peroxidase activity (initiation phase) followed by decrease has been found in IBA-treated cuttings. During initiation phase the lignin content was almost similar to that on day 0 in genotype while it was reduced at by about 50% in genotype at the respective time. Microscopic observations revealed anatomical differences between genotypes. According to this study, the and genotypes display differences in anatomy, lignin content, activity of soluble peroxidases and the electrophoretic patterns of soluble anionic peroxidase isoforms. The A3-anionic peroxidase isoform could be used as biochemical marker to distinguish and genotypes of E. cretica and seems to be correlated to lignin synthesis in rooting process.     

A relationship between irradiation, carbohydrates and rooting in cuttings of Pisum sativum

Rooting ability was studied for cuttings derived from pea plants ( Pisum sativum , L. cv. Alaska) grown in controlled environment rooms. When the cuttings were rooted at 70 μmol m⁻² s⁻, ¹ (photosynthetic photon flux density) or more, a stock plant irradiance at 100 μmol m⁻² s⁻¹ decreased rooting ability in cuttings compared to 5 μmol m⁻², s⁻¹, However, cuttings rooted at 160 μmol m⁻² s⁻¹ formed more roots compared to 5 (μmol m⁻² s⁻¹. Although a high irradiance increased the number of roots formed, it could not overcome a decreased potential for root formation in stock plants grown at high irradiance. Light compensation point and dark respiration of cuttings decreased by 70% during the rooting period, and the final levels were strongly influenced by the irradiance to the cuttings. Respiratory O₂ uptake decreased in the apex and the base of the cutting from day 2 onwards, whereas a constant level was found in the leaves. Only the content of extractable fructose, glucose, sucrose and starch varied during the early part of the rooting period. We conclude that the observed changes in the cuttings are initiated by excision of the root system, and are not involved in the initiation of adventitious roots.     

Methyl gallate and its 3-glucoside promote rooting in bean cuttings

Methyl gallate stimulated adventitious root formation in cuttings of bean (Phaseolus vulgaris L.). This polyphenol was quickly metabolized into 3-glucosyl methyl gallate to such an extent that 4 h after application no methyl gallate was detected. The isolated glucoside when supplied exogenously at 0.5 mM also enhanced rooting; the effect was 2-fold greater than that of methyl gallate. The glucoside persisted in the cuttings for 72 h after treatment. Because methyl gallate is rapidly transformed to a stable glucoside, we suggest that the root stimulation effect could be ascribed to its glucoside.     

Effect of Gibberellic Acid and Some Phenols on Flowering of Impatiens balsamina, a Qualitative Short-day Plant

GA₃ as well as SA (salicylic acid) and β-N (β-naphthol) induce floral buds in Impatiens balsamina under strictly non-inductive photoperiods. The floral bud initiation is accelerated when 1 mg/1 SA is used in combination with 100 mg/1 GA₃. 100 mg/1 GA₃+ 1 mg/1 SA and 100 mg/1 GA₃+ 100 mg/1 β-N increase the number of floral buds as compared with 100 mg/1 GA₃ alone.     

扦插时间对蝟实插穗生根率和相关指标的影响及生根效应综合评价

在3月5日至9月5日期间,以蝟实( Kolkwitzia amabilis Graebn.)顶端枝条作为插穗,每隔10 d扦插1次,对扦插10 d后插穗的生根率,内源吲哚乙酸( IAA)、脱落酸( ABA)和赤霉素( GA3)含量,超氧化物歧化酶( SOD)、过氧化物酶( POD)和过氧化氢酶( CAT)活性以及可溶性糖和可溶性蛋白质含量进行比较,对生根率与上述8项指标进行相关性分析和回归分析,并对这8项指标进行主成分分析;在此基础上,对不同扦插时间插穗的生根效应进行隶属函数值分析和综合评价。结果显示：随扦插时间推移,蝟实插穗的生根率总体上呈现先升高后降低的变化趋势,5月下旬至7月中旬期间扦插的插穗生根率相对较高,并以6月中旬至7月中旬期间扦插的插穗为最高,总体在70%以上。随扦插时间推移,插穗中IAA和可溶性糖含量均呈波动变化趋势;而插穗中的ABA含量、POD活性和可溶性蛋白质含量总体呈先逐渐升高后逐渐降低的趋势,GA3含量和CAT活性变化不明显,SOD活性总体上呈缓慢升高的趋势。相关性分析结果表明：蝟实插穗的生根率与IAA含量、POD活性和可溶性蛋白质含量呈极显著(P<0.01)正相关,与CAT活性呈极显著负相关。主成分分析结果显示：前2个主成分的累计贡献率为84.383%,说明前2个主成分能够基本反映蝟实扦插生根的主要影响因子,其中第1主成分中可溶性蛋白质和IAA含量为主要因子,第2主成分中CAT活性为主要因子。综合评价结果显示：5月下旬至7月中旬期间扦插的蝟实插穗的综合评价指数(D)较高,为0.747~0.983,与插穗生根率的实测值基本吻合。研究结果表明：在中国西北地区,蝟实插穗的适宜扦插时间为5月下旬至7月中旬,并以6月中旬至7月中旬为最佳;扦插过程中喷施适当浓度IAA溶液可以提高插穗的生根率。     

Determination and Differentiation of Leaf and Petal Primordia in Impatiens balsamina

The development of primordia as leaves, petals, or as organsintermediate between leaves and petals can be regulated by photoperiodin Impatiens. In intermediate organs only some parts of theorgan differentiated as petal, and then only in some cell layers.Allometric measurements of primordium shape suggested that intermediateorgans may begin development as petals, and that their intermediatecharacter at maturity resulted from a switch of some parts ofthe organs from petal to leaf development when the primordiawere between 0.5 and 1 mm long. In reverted apices made to re-flower,primordia were not completely determined as leaves until theywere about 750 µm long. Determination typically occurredfirst at the tips and last at the bases of these primordia.The determination of primordia as leaves or petals in Impatiensis discussed in relation to primordium determination in otherspecies. It is suggested that the lack of commitment to flowermay result in relatively late primordium determination in Impatiens. Impatiens balsamina, determination, differentiation, leaf and petal development, flowering, reversion     

Effect of decapitation, phosfon D and cycocel on the flowering of Impatiens balsamina exposed to varying numbers of short days

Impatiens balsamina L., a qualitative short day plant, requiresmore short days for the development of floral buds into flowersthan for their initiation. Phosfon D and cycocel reduce thenumber of short days required for flowering, increase the numberof floral buds and flowers and delay their reversion to vegetativegrowth when transferred to noninductive conditions. The effectof decapitation of the main shoot subsequent to the emergenceof floral buds resembles that of retardants indicating thatthe effect of the latter in flower promotion in this plant maybe by virtue of their effect on cessation of apical dominanceas a consequence of which reserve food materials may be channeledto axillary floral buds enabling them to develop into flowers. (Received January 9, 1969; )