Effect of three growth regulators on the floral bud drop, duster, and berry characters as weil as fruit quality in Thompson Seedless grape was studied. The clusters were sprayed 18 and 10 days before anthesis (S 1 and S 2 stages) with GA 3 (5, 10, 20, 50 ppm) and IAA and PCPA (2.5, 5, 10, 20 ppm each). All treatments reduced floral bud drop in comparison to control. However, significantly less drop (about 22 to 41 per cent) occurred when GA 3 (20 and 50 ppm), IAA (10 and 20 ppm) and PCPA (20 ppm) were applied. A better response, though non-significant, was clearly demonstrated when the clusters were treated at the earlier pre-bloom stage (S 1 ). Cluster weight and the berry weight were also significantly increased. GA 3 at all concentrations and IAA (20 ppm) resulted in significant elongation of clusters. PCPA treatments suggestively increased TSS and lowered the acidity level, whereas GA 3 and IAA did not have any appreciable effect on these attributes. Einflus von Wachstumsregulatoren auf das Durchrieseln der Blutenknospen sowie auf Traubenmerkmale und Qualitat von Thompson Seedless ( Vitis vinifera L.) Der Einflus von drei Wachstumsregulatoren auf das Abfallen der Blutenknospen sowie auf Merkmale und Qualitat der Beeren und Trauben bei der Sorte Thompson Seedles wurde untersucht. Die Infloreszenzen wurden 18 und 10 Tage vor der Anthese (Stadien S 1 und S 2 ) mit GS 3 (5, 10, 20, 50 ppm), IES und PCPA (je 2,5, 5, 10, 20 ppm) bespruht. Alle Behandlungen verringerten das Durchrieseln im Vergleich zur Kontrolle. Bei Anwendung von GS 3 (20 und 50 ppm), IES (10 und 20 ppm) und PCPA (20 ppm) war das Verrieseln jedoch signifikant verringert (ca. 22-41 %). Ein deutlich verbessertes, allerdings nicht statistisch abzusicherndes Ergebnis zeigte sich, wenn die Infloreszenzen in dem fruheren Vorblutenstadium (S 1 ) behandelt wurden. Trauben- und Beerengewicht waren gleichfalls signifikant erhoht. GS 3 (bei allen Konzentrationen) und IES (bei 20 ppm) hatten eine signifikante Verlangerung der Trauben zur Folge. PCPA-Behandlungen bewirkten eine schwache Erhohung der TSS und eine geringfugige Erniedrigung der Sauren, wahrend GS 3 und ES darauf keinen merklichen Einflus hatten.

The effect of some of the gibberellins (GA 3 , GA 4+7 und GA 13 ) on seed germination and subsequent seedling growth of Early Muscat grape was investigated. The after-ripened seeds were treated with 0, 50, 100, 250, 500 and 1000 ppm concentrations of each gibberellin. All gibberellins, except GA 4+7 , at concentrations beyond 50 ppm promoted germination. Generally, the lower concentrations were found more efficacious for enhancing the germination. GA 4+7 at 1000 ppm completely inhibited the germination. The activity of GA 3 was gradual and regular, whereas GA 4+7 and GA 13 showed swift activity with a narrow germination-promotive-concentrationrange. The variable influence of gibberellins an seedling growth was also observed. Der Einflus der Gibberelline GA 3 , GA 4+7 und GA 13 auf die Samenkeimung und das anschliesende Samlingswachstum bei der Rebensorte Early Muscat ( Vitis vinifera ) Bei der Rebensorte Early Muscat wurde der Einflus einiger Gibberelline (GA 3 , GA 4+7 und GA 13 ) auf die Samenkeimung und das anschliesende Wachstum der Samlinge untersucht. Die nachgereiften Samen wurden jeweils mit Gibberellinkonzentrationen von 0, 50, 100, 250, 500 und 1000 ppm behandelt. Alle Gibberelline, mit Ausnahme von GA 4+7 , forderten bei Konzentrationen uber 50 ppm die Samenkeimung. Im allgemeinen erwiesen sich niedrigere Konzentrationen hierbei als wirksamer. 1000 ppm GA 4+7 hemmten die Keimung vollkommen. Die Wirkungskurve des GA 3 in Abhangigkeit von der Konzentration verlief stetig und ausgeglichen, wahrend sie bei GA 4+7 und GA 13 einen raschen Anstieg mit einem schmalen keimungsfordernden Konzentrationsbereich zeigte. Auch beim Wachstum der Samlinge wurde der unterschiedliche Einflus der Gibberelline beobachtet.

Mobilization of free sugars from vegetative tissues to grain and their transformation to starch in relation to activities of some relevant enzymes during growth and development were investigated in wheat (Triticum aestivum L.). Vegetative tissues, viz. flag-leaf, flag-leaf sheath, nodes and internodes contained high concentration of free sugars from 70 DAS to 18 DPA and that was in the order of accumulation--flag-leaf sheath> flag-leaf and internodes > nodes. In these tissues, major portion of 14C appeared in endogenous sucrose, irrespective of the nature of (U-14C]-sugars supplied. In photosynthetic structures above flag-leaf node, namely peduncle, rachis and bracts, the free sugar make-up was maximum at anthesis (90 DAS). Activity of soluble acid invertase (EC 3.2.1.26) was high in these tissues during early stages of grain growth but reverse was true for soluble neutral invertase (EC 3.2.1.27) activity. In apical and basal portions of grain, free sugars were more or less similarly distributed in concentration. Linear and rapid accumulation of starch in endosperm paralleled with a decline in accumulation of this polymer in pericarp-aleurone. In the latter tissue, the activities of starch hydrolyzing enzymes, i.e alpha- and beta-amylases (3.2.1.1 and 3.2.1.2) were high during initial stages of grain growth. During active grain-filling, alkaline inorganic pyrophosphatase (EC 3.6.1.1) seemed to play a vital role during starch accumulation in endosperm, whereas the involvement of 3-PGA phosphatase (EC 3.1.3.38) was almost confined to pericarp-aleurone. Impairement of ear head photosynthesis by shading depressed starch synthesis (approximately 50%) indicating, thereby, the significant role of current photosynthates during grain-filling. The results suggested that grain growth in wheat was influenced by an efficient operation of source as well as regulatory factors, including enzymes, constituting intrinsic potential of grain sink.

Arbuscular mycorrhizae (AM) are the most common endophytes in various types of soil which enters into symbiotic relationship with higher plants (7). The endophytes colonize roots and enhance plant growth by increasing their nutrient up take, 'which results in increased yield. The pulses such as soybean, lentil, chickpea, mung bean have been found to be highly compatible for AM association (1, 6, 11, 12). However, AM fungi may vary in spore germination and root colonization potentiality according to host and endophyte species, which affect the nutrient uptake and plant growth (8, 13). The soil samples examined from different parts of Punjab confirmed the presence of Glomus and Gigaspora species, out of which Glomus fasciculatum was the most common. The present investigation is to compare for the root colonization, spore population and plant growth responses in chickpea inoculated with two species each of Glomus and Gigaspora.

Indole-acetic acid (IAA) and abscisic acid (ABA) were fed throughcomplete liquid medium (containing 2, 4, 8% sucrose) to detached earheads of sorghum. The effect of these phytohormones on interconvertion ofsugarsand their transformation to starch in relation to the activities ofα-, β-amylases, sucrose-synthase (synthesis), sucrose-phosphatesynthase and soluble invertases was studied in the grain. This effect on theuptake of (U-14C) sucrose by detached ear heads and incorporation of14C into free sugars and starch of grain and into free sugars ofinflorescence parts was also studied. At concentrations of up to 4%sucrose in the culture medium, IAA increased the content of total free sugarsinthe grain. However, accumulation of starch and activities of α- andβ-amylases increased when lAA was present even beyond the 4%sucroseconcentration in the culture medium. At all sucrose concentrations, the effectsof ABA and IAA were opposite. With 4% sucrose, both phytohormones causedmaximum accumulation of starch in the grain. ABA enhanced the relativeproportion of sucrose in the sugar pool with a concomitant reduction in theactivities of soluble acid (pH 4.8) and neutral (pH 7.5) invertases. Incontrast, IAA decreased the sucrose proportion of grain sugars with asimultaneous elevation and reduction in the activities of invertases andsucrose-phosphate synthase, respectively. Irrespective of sucrose concentrationin the culture medium, the activity of sucrose synthase (synthesis) wasenhancedwith IAA as well as ABA at their 10 μM concentration. IAA alsoenhanced incorporation of 14C from (U-14C) sucrose intothe EtOH extract (principally constituted by free sugars) and starch of thegrain, but ABA caused the reverse effect. Based on the results, it is suggestedthat IAA and ABA have contrasting effects on the transformation of sucrose tostarch in sorghum grain where its capacity to synthesise starch is modulatedpositively by IAA and negatively by ABA.

Free sugar interconversion and activities of soluble acidic (pH 4.8) and neutral (pH 7.5) invertases, sucrose synthase (synthesis) and sucrose phosphate synthase were investigated in the growing nodes and internodes of sorghum (Sorghum vulgare). The results were substantiated with incorporation of 14C from supplied sucrose and hexoses into endogenous sugars of these stem tissues. With the advancement in plant growth, the content of total free sugars in apical nodes and internodes increased till 70 DAS (flowering stage) followed by a decline. In the corresponding basal tissues, the sugar build-up continued even beyond this stage of plant growth. Compared with basal stem tissues, the apical ones contained high activities of soluble invertases and a low proportion amongst free sugars of sucrose. The activities of sucrose-hydrolyzing enzymes were higher as compared with those of sucrose-synthesizing ones in both nodes and internodes and with the growth of plant, the activity of neutral invertase increased in these tissues. More 14C from supplied sucrose and hexoses appeared in extracted sugars from cut discs of apical nodes and internodes in comparison with their basal counterparts. 14C from supplied sucrose appeared in glucose, fructose and from supplied hexoses appeared in sucrose. The results suggest that in apical nodes and internodes, where a rapid cell division and cell expansion occur, sucrose is obligatorily inverted to meet the increased requirement of hexoses and there is a compartmentalized synthesis and cleavage of sucrose in the nodes and internodes of growing sorghum plant.

Detached ears of sorghum (So rghum vlligare) were cultured in complete liquid medium containing Pi or PPi (20 mM). Effect of these inorganic phosph;;tes on conversion of sucrose to starch in relati on to the acti vity of alkaline inorganic pyrophosphatase (EC 3.6. 1. 1) was studied . Both Pi and PPi reduced the accumulation of biomass and starch in rary()p~i~ and this reduction was more pronounced with advancement in culturing period. Amongst endogenous sugar~ of ca ryopsi s. the relative proportion of sucrose increased with either of these phosphates. With elevati on in endogenous levels of Pi and PPi in earyopsis, there was a corresponding decline in the activity of alkaline inorganic pyrophosphatase. Addit illn or these inorgani c phosphates in culture medi um also reduced the incorpo rat ion of 14C from (U_1 4C)-sucrosc into EtOH ext ract (principally constituted by free sugars) and starch of caryopsis. Accompanying thi s reduc ti on, there was an incrc:lse ill I~C incorporation into sucrose. Based on these results, it has been suggested that in sorghum caryopsis an inhib it ion of the act ivity of alkaline inorgani c pyrophosphatase resu lts in lowering starch accumulation .

Abstract The path of carbon from sucrose to starch in developing grains appears to be different in wheat (Triticum aestivum) and sorghum (Sorghum bicolor). In this paper we present indirect evidence in support of this hypothesis. Detached ears, carrying actively metabolising grains, were cultured in complete liquid media manipulated with respect to inorganic phosphates and organic acids. 14C‐incorporation studies indicated a higher level of metabolism of sucrose before starch formation in sorghum grain as compared to that in wheat grain. Starch and protein contents drastically decreased in sorghum grain in response to exogenously‐supplied inorganic phosphate and inorganic pyrophosphate. In contrast, these inorganic phosphates had no such effect on starch and protein accumulation in wheat grain, a‐ketoglutarate and citrate in sucrose‐free culture medium increased the starch content of wheat grain. Conversely, these organic acids markedly decreased the starch content of sorghum grain. This difference in the...

Using liquid culturing of detached inflorescences of chickpea ( Cicer arietinum ), manipulations with respect to sugars and amino nitrogen were done on the feeding sap entering the developing pods. The effects of such manipulations on the accumulation of biomass in seed, starch and protein in cotyledons and the activities of soluble acid and neutral invertase (EC 3.2.1.26), sucrose synthase (cleavage, EC 2.4.1.13), glutamate oxaloacetate transaminase (EC 2.6.1.1) and glutamate pyruvate transaminase (EC 2.6.1.2) in pod tissues were investigated. Compared with supplied hexoses, addition of sucrose in the culture medium resulted in higher accumulation of biomass in seed and decapitation of detached inflorescence did not affect this biomass accumulation. Appearance in seed tissues of over 70 % of 14 C in extracted sugars for sucrose alone indicated entry into seed of translocated sucrose as such and/or its reconstitution in these tissues. Comparative effect of exogenously-fed cold sugars on incorporation of 14 C from sucrose into EtOH-soluble products of seed tissues indicated that a minimum level of sucrose in transport stream is essential for an effective unloading of this sugar into seeds. Whereas in pod wall and seed coat, the cleavage of sucrose is principally catalysed by soluble neutral invertase, in cotyledons both soluble neutral invertase and sucrose synthase (cleavage) are involved. The accumulation of proteins in cotyledons was significantly higher with amides, compared with inorganic nitrogen, added to the culture medium. In pod wall and seed tissues, the activity of glutamate oxaloacetate transaminase was much higher than that of glutamate pyruvate transaminase. Increased supply of glutamine at an adequate fixed level of sucrose resulted in diversion of sucrose from starch to protein synthesis with concurrent increase in the activities of both transaminases in cotyledons.

Effect of sodium fluoride (10-50 mM) on the activities of sucrose metabolizing enzymes and alkaline inorganic pyrophosphatase in relation to the transformation of free sugars to starch was studied by culturing detached ears of sorghum (Sorghum bicolor) in complete liquid medium for 4 and 7 days. Addition of fluoride to culture medium reduced the contents of dry weight, total free sugars and starch of the grains. This ion stimulated the activities of sucrose metabolizing enzymes viz, soluble acid-, neutral invertases (EC 3.2.1.26) and sucrose synthase (EC 2.4.1.13). However, the activity of sucrose phosphate synthase (EC 2.4.1.14) remained unaffected. The activity of alkaline inorganic pyrophosphatase (EC 3.6.1.1) decreased with fluoride and this was concomitant with an increase in the contents of inorganic pyrophosphate (PPi) and reducing sugars. Culturing detached spikelets in 10-50 mM fluoride and pretreating isolated endosperm in presence of 50 mM fluoride drastically reduced the incorporation of C-14 into starch from supplied [U-C-14]-sucrose or glucose or fructose. Based on these results, we infer that low activity of alkaline inorganic pyrophosphatase by fluoride led to an increased accumulation of PPi in grain amyloplasts which in turn inhibited the production of starch.

Metabolic changes in the contents of sucrose and hexoses in relation to the activities of invertase, sucrose synthase and sucrose-phosphate synthase in early (CoJ 64) and late (Co 1148) maturing cultivars of sugarcane have been studied. During early stages of cane growth, lower activities of sucrose synthase and sucrose-phosphate synthase in leaf blade In CoJ 64 over Co 1148 were observed. However, sucrose content in sheath/blade was higher in CoJ 64 than in Co 1148. With the advancing age, the activity of soluble acid invertase (pH 5.4) in stem declined more rapidly in CoJ 64. This resulted in building up of high ratio of sucroselinvert sugars in stem tissue of this cultivar. Feeding uniformly-labelled sucrose and glucose to the cut discs of leaf sheath resulted in higher uptake of 14C in CoJ 64 than in Co 1148. Uptake by stem tissue discs of 14C from sucrose was less than that from hexoses. Based on these results, it is suggested that (i) the rapid fall in the activity of soluble acid invertase in stem concomitant with fast accumulation of sucrose in this tissue is an index of early maturity of the cane, and (ii) high content of sucrose in sheath is a reflection of an efficient translocation of this sugar in early maturing cultivars.

Metabolism of free sugars, particularly sucrose, in various plant tissues enroute from leaf sheaths to grains in growing pearl millet was studied. With the enhancement in growth, the levels of both reducing and non-reducing sugars declined in middle and basal leaf sheaths but increased in flag leaf sheath towards plant maturity. In sheath, wall-bound invertase was more active than soluble invertases and the activities of all these enzymes rose towards maturity. Besides hexoses and sucrose, some fructose polymers were also detected in the internodes. In contrast with internodes, where the levels of total free sugars declined till around anthesis, in penultimate node their levels continuously increased, but attained peak values at 65 CAS in middle- and basal nodes. In both these tissues, arriving sucrose encounters invertases but in nodes wall-bound invertase appears to be the pivotal one. On feeding (U-14C)-sucrose to the detached ear-heads a large proportion of 14C was incorporated into hexoses alone in peduncle and rachis. PCMBS and HgCl2 inhibited the metabolism of sucrose supplied to peduncle and rachis pointing to the involvement of invertases in sucrose cleavage in these organs. Through the regulated operation of invertase(s), the nodes seem to maintain a controlled flow of free sugars from source to sink tissue.

Metabolism of free sugars in relation to the activities of sucrose cleaving- and nitrogen assimilating enzymes in the developing nodules of chickpea (Cicer arietinum) was investigated. Throughout nodule development, sucrose was found to be the principal sugar of the host cytosol and this sugar accumulated in the nodules towards their maturity. On feeding uniformly-labelled [C-14]sucrose or [C-14]glucose or [C-14]fructose through cut system (intact with roots and nodules), the major proportion of C-14 appeared in sucrose of stem and root tissues showing conversion of hexoses into sucrose in stem before their transport to roots and nodules. Incorporation of C-14 into sucrose on feeding [C-14]glucose or [C-14]fructose directly to nodules also indicated the capacity of nodules to convert hexoses into sucrose. The nitrogen fixation capacity in nodules was high at 45 and 60 DAS (days after sowing). Alkaline invertase (EC 3.2.1.26) and sucrose synthase (cleavage direction, EC 2.4.1.13) showed maximum activities in nodule cytosolic fraction at 45 DAS and 60 DAS, respectively. The activity of sucrose synthase (synthesis direction) in nodule cytosol was high at or near maturity. Activities of both aspartate aminotransferase (EC 2.6.1.1) and glutamine synthetase (EC 6.3.1.2) in nodule cytosol were high at the time of maximum nitrogenase activity in nodules. NADP(+)-dependent isocitrate dehydrogenase (EC 1.1.1.41) activity was 10-15 times more in cytosol than in the bacteroids. The possible role of isocitrate, dehydrogenase and a minimum requirement for 2-oxoglutarate synthesis to support ammonia fixation has been discussed.

Kluyveromyces fragilis (NCIM 3217), Kluyveromyces marxianus (NCIM 3231), Hansenula polymorpha (NCIM 3377). Pichia fermentan (NCIM 3408), Pichia polymorpha (NCIM 3419) and Debaryomyces castellii (NCIM 3446) were grown on an inulin-based growth medium. Only K. fragilis produced extracellular inulinase with a maximum after 36 h of growth at 25-27-degrees-C. Sucrose and fructose were weak inducers of inulinase as compared to inulin whereas with glucose the inulinase level was minimal. An aqueous extract of chicory roots containing 1%, fructan was a better carbon source than inulin and peptone was the best nitrogen source for the production of inulinase. The maximum yield of inulinase was about 7 units cm-3 of medium. The invertase to inulinase ratio of 10 in the culture filtrate was reduced to 1.6 on purifying inulinase by ethanol precipitation followed by chromatography on Sephadex G-200, DEAE-cellulose and CM-cellulose columns. Using this purification procedure. inulinase was purified 26-fold. With inulin as substrate, the shape of the velocity curve was nearer to a sigmoidal pattern whereas with sucrose the curve was hyperbolic. The molecular weight of inulinase was determined as 250 +/- 10 kDa. The crude and purified inulinase preparations did not release sucrose or oligosaccharides from inulin, indicating that the enzyme has primarily exo-inulinase activity. Using the metal-link chelation method, 40% of inulinase was immobilised on cellulose. Maximum activity of crude, purified and immobilised inulinase preparations was observed at 55-degrees-C. The half-life of immobilised inulinase at 25-degrees-C was 5 days.

Inulin has been found to be a better inducer of invertase than sucrose and this led to an increased secretion of invertase in the medium on using inuli

Chickpea (Cicer arietinum) cvs C-214 and GL-769 are relatively tolerant to water deficit than cvs PBG-1 and G-130. The seeds of cvs C-214 and PGB-1 were germinated in dark for six days under reduced water potential induced by polyethylene glycol. Under these conditions, the observed decrease in seed germination and in length and biomass of epicotyls and hypocotyls was more in PBG-1 as compared to C-214. Water stress caused an increase in total soluble sugars and bound fructose in cotyledons, hypocotyls and epicotyls of both the chickpea cultivars irrespective of their sensitivity to water stress. The alpha-amylase (EC 3.2.1.1) activity in cotyledons of stressed and normal seedlings of PBG-I was significantly less as compared to its activity in C-214. A decrease in starch content of embryonic axis (hypocotyl and epicotyl) and an increase in cotyledons under water stress in C-214 and PBG-1 cultivars was related to the activity of a-amylase in these tissues. The depletion of raffinose series oligosaccharides was delayed in the cotyledons of stressed seedlings of both the cultivars. This observation along with decrease in the alpha-amylase activity and slow depletion of starch in cotyledons suggested a decreased formation of sucrose in cotyledons of stressed seedlings. As compared to chickpea cvs PBG-1 and G-130, in chickpea cvs C-214- and GL-769, the specific activity of alpha-amylase and total amylase was high in cotyledons of dry seeds and seeds germinating in absence of water stress.

Detached ears of wheat were cultured in liquid medium manipulated for sucrose and glutamine contents, and the accumulation of starch and protein in relation to the activities of sucrose cleaving—, ammonia assimilating—, and transaminating enzymes was studied in the grain. With an increase in the concentrations of sucrose from 44 to 176 mM and glutamine from 6.4 to 25.7 mM (keeping their ratio at a constant value of 7:1), the contents of starch and protein increased in the grains. However, when the grains were cultured in the medium containing 8.5 to 34 mM glutamine and a fixed concentration of 117 mM sucrose, there was a gradual increase in protein and decrease in starch content in the grain. By such manipulation in the liquid medium, the content of free amino acids also increased in the grain up to 12 days culturing. Amongst sucrose cleaving enzymes, the activities of sucrose-UDP glucosyl transferase and soluble alkaline invertase were much lower than the activity of soluble acid invertase. At high concentration (34 mM) of glutamine in the medium, containing 117 mM sucrose, there was drastic decrease in the activities of soluble acid invertase and UDPG pyrophosphorylase but the activities of ADPG pyrophosphorylase, alkaline inorganic pyrophosphatase, glutamate dehydrogenase, glutamate oxaloacetate transaminase and glutamate pyruvate transaminase increased in the grain with increase in glutamine concentration in the culture medium. Evidently, an increase in the level of amino nitrogen, coupled with an optimum sucrose concentration in the grain raised through liquid culturing enhances the conversion of sucrose to protein at the cost of starch accumulation in wheat.

Inulin is a reserve carbohydrate in the roots of Cichorium intybus L. It is hydrolysed by inulinase during flowering and seed formation. Seventy to eighty five percent of inulinase was found to be firmly bound to the cell wall. The quantity of cell wall-bound inulinase proved to be too low to be used for commercial purposes. The level of soluble inulinase in the vascular bundles was generally higher than that in the root cortex. The activity of bound inulinases of vascular bundles and cortex was characterized by a sigmoidal velocity curve with increasing inulin concentration. Sucrose was a non-competitive inhibitor of bound inulinase from vascular bundles. It may play an important role in regulating the activity of this enzyme under in vivo conditions. Metabolites like phosphoenol pyruvate, 2-phosphoglycerate, 6-phosphogluconate, and nucleotides (ADP, ATP, UDP, UTP and UDP-glucose) changed the sigmoidal pattern of inulinase activity of vascular bundles to a near-hyperbolic pattern, thus suggesting enhancement of inulinase activity at low and inhibition at high inulin concentrations. Hg2+ was a very strong inhibitor of inulinases. The temperature optimum of bound inulinases from vascular bundles (45 °C) was higher than that of other inulinases (37 °C).