CsABF3-activated CsSUT1 pathway is implicated in pre-harvest water deficit inducing sucrose accumulation in citrus fruit

Pre-harvest water deficit(PHWD)plays an important role in sugar accumulation of citrus fruit.However,the mechanism is not known well.Here,it was confirmed that PHWD promoted sucrose accumulation of citrus fruit,but had limited effect on fructose,glucose and total acid.A sucrose transporter,Cs SUT1,which localizes to the plasma membrane,was demonstrated to function in sucrose transport induced by PHWD.Compared to wild-type,Cs SUT1 overexpression in citrus calli stimulated sucrose,fructose and glucose accumulation,while its silencing in juice sacs reduced sucrose accumulation.Increased sugar accumulation in transgenic lines enhanced plant drought tolerance,and resulted in decreased electrolyte leakage,malondialdehyde and hydrogen peroxide contents,as well as increased superoxide dismutase activity and proline contents.An abscisic acid(ABA)-responsive transcription factor,Cs ABF3,was found with a same expression pattern with Cs SUT1 under PHWD.Yeast one-hybrid,electrophoretic mobility shift assay and dual-luciferase assays all revealed that Cs ABF3 directly bound with the Cs SUT1 promoter by ABA responsive elements.When Cs ABF3 was overexpressed in citrus calli,the sucrose,fructose and glucose concentration increased correspondingly.Further,transgenic studies demonstrated that Cs ABF3 could affect sucrose accumulation by regulating Cs SUT1.Overall,this study revealed a regulation of Cs ABF3 promoting Cs SUT1 expression and sucrose accumulation in response to PHWD.Our results provide a detail insight into the quality formation of citrus fruit.

Genome-wide identification and function analysis of the sucrose phosphate synthase MdSPS gene family in apple

Sucrose phosphate synthase(SPS)is a rate-limiting enzyme that works in conjunction with sucrose-6-phosphate phosphatase(SPP)for sucrose synthesis,and it plays an essential role in energy provisioning during growth and development in plants as well as improving fruit quality.However,studies on the systematic analysis and evolutionary pattern of the SPS gene family in apple are still lacking.In the present study,a total of seven MdSPS and four MdSPP genes were identified from the Malus domestica genome GDDH13 v1.1.The gene structures and their promoter cis-elements,protein conserved motifs,subcellular localizations,physiological functions and biochemical properties were analyzed.A chromosomal location and gene-duplication analysis demonstrated that whole-genome duplication(WGD)and segmental duplication played vital roles in MdSPS gene family expansion.The Ka/Ks ratio of pairwise MdSPS genes indicated that the members of this family have undergone strong purifying selection during domestication.Furthermore,three SPS gene subfamilies were classified based on phylogenetic relationships,and old gene duplications and significantly divergent evolutionary rates were observed among the SPS gene subfamilies.In addition,a major gene related to sucrose accumulation(MdSPSA2.3)was identified according to the highly consistent trends in the changes of its expression in four apple varieties(‘Golden Delicious’,‘Fuji’,‘Qinguan’and‘Honeycrisp’)and the correlation between gene expression and soluble sugar content during fruit development.Furthermore,the virus-induced silencing of MdSPSA2.3 confirmed its function in sucrose accumulation in apple fruit.The present study lays a theoretical foundation for better clarifying the biological functions of the MdSPS genes during apple fruit development.

Study on the Preparation Process Optimization of Plywood Based on a Full Biomass Tannin-Sucrose Wood Adhesive

Biomass adhesive is conducive to decreasing the dependence of the wood adhesive industry on synthetic resin based on fossil resources and improving the market competitiveness of adhesives.It is also a critical breakthrough to realize the goal of carbon peaking and carbon neutrality in the wood industry.In this study,a full biomass wood adhesive composed of tannin and sucrose was developed and applied successfully to the preparation of ply-wood.The preparation technique of plywood was optimized,and the chemical structure,curing performance,crystallization property and thermal performance of the adhesive were investigated.Results showed that:(1)hot-pressing temperature played a decisive role in the performances of tannin-sucrose composite adhesives and it also had a very significant influence on the water resistance of plywood.(2)The preparation of tannin-sucrose composite adhesive was a process in which sucrose was transformed into furan aldehydes and then made cross-linking reaction with tannin.These composite adhesives could only get good bonding performances when the curing temperature was above 210℃.(3)The optimal plywood preparation technique was:hot-pressing tem-perature of 220℃,hot-pressing time of 1.2 min/mm,m(tannin):m(sucrose)of 60:40,and adhesive loading of 160 g/m^(2).The wet bonding strength in boiling water of the prepared plywood was 0.83 MPa,meeting the strength requirements of Type-I plywood in the standard of GB/T 17657-2013.(4)The curing temperature of tannin-sucrose composite adhesive was further decreased by lowering the temperature during the transformation of sucrose into 5-HMF,which was a key in subsequent research.

Research on Variation in Sucrose Content among Different Tartary Buckwheat Genotypes

[Objective] The aim was to determine the difference in sucrose content of different tartary buckwheat sources,so as to screen low-sucrose buckwheat materials.[Method] The sucrose contents of 35 tartary buckwheat materials from different regions were measured.[Result] The sucrose content of the 35 tartary buckwheat materials varied from 0.007 7% to 0.208 9% with an average of 0.051 8%.There was some difference among the tartary buckwheat materials from different regions.The seeds from Hezhang in Guizhou had higher sucrose content,while the seeds from Nayong in Guizhou had lower sucrose content.[Conclusion] The content of sucrose was significantly low in tartary buckwheat,which could be popularized as a kind of low-sugar crop.

Regulation of Sucrose and Zinc on Root System Growth in Rice

[Objective] The aim was to study the relationship between urcrose, zinc and the root system growth in rice. [Method] Changes of root system growth, ROS generation and root system proton export ability were analyzed in rice （Oryza sativa L. cv Zhonghua No.11） treated with different concentrations of Zn （NO3）3 sucrose, com- bined sucrose and Zn （NO3）3 mannitol as well as mannitol plus Zn （NO3）2. [Result] The results showed that treatment with 1-3 mM Zn（NO3）2 resulted in significant increases in total root length /number and in accumulation of H202 and 02- but decreases in root system proton export ability. With the exception of shoot length, the length of primary, adventitious, and lateral roots, and the number of adventitious, and lateral roots on primary /adventitious roots were all influenced by different concentrations of sucrose. High concentrations of sucrose caused increases in H202 and O2-, starva- tion or high concentrations of sucrose reduced root system proton export ability after treating with or without Zn. However, at the same concentration of sucrose, different changes of these indicators were observed between Zn and non-Zn treatments. The regulation of root system growth induced by sucrose was marked different from that of mannitol at the same concentration of 5%, suggesting that these effects were caused by sugar signal but not by osmotic potential. [Conclusion] This study indicat- ed that both sucrose and Zn play important roles in the regulation of rice root system growth.

Effect of Low Night Temperature Treatment on Sucrose Synthesis Ability of Tomato Leaves in Seedling Stage

[Objective] The aim was to explore the effects of low night temperature treatment on sucrose synthesis ability of tomato leaves in seedling stage.[Method] Effects of low night temperature of 6 ℃（with 15 ℃ as control）on the sucrose synthesis ability of tomato leaves were studied after 1,3,5,7 d of treatment.[Result] The contents of fructose,glucose and sucrose in tomato leaves were higher than control at 6：00 during the treatment of low night temperature,but in contrast at 11：00.The contents of fructose,glucose and sucrose in tomato leaves of low night temperature treatment and control group at 6：00 were lower than that at 11：00.The content of starch in tomato leaves was higher than control at 6：00 and 11：00 during the treatment.And the activities of sugar metabolism enzymes of tomato were changed by the treatment of low night temperature.The activities of acid invertase（AI）and neutral invertase（NI）were higher than those of control,while the activities of sucrose synthase（SS）and sucrose phosphate synthase（SPS）were lower than control at 6：00 and 11：00 during the treatment.The activity of all the enzymes at 11：00 of low night temperature treatment plants treated for 1,3,5,7 d was higher than that at 6：00.Compared to 6：00,the invertase activity of the control plant decreased,while the synthetase activity increased.The activity of sucrose synthase（SS）was decreased for treated plants,and the increase amount of sucrose content in leaves was lower than that of control at 11：00 during the treatment,indicating that the sucrose synthesis ability of tomato leaves was decreased by the treatment of low night temperature.[Conclusion] The results in this study had provided theoretical basis for the environmental control of high-yield cultivation of tomato.

Effects of Sucrose Concentration and Sunlight on the Cutting of Coleus blumei

[Objective] To provide scientific bases for the propagation of Coleus blumei. [Method] With the healthy branches of potted Coleus blumei as experiment materials, effects of sucrose concentration on the rooting of Coleus blumei cuttings as well as effects of sunlight on its growth were studied. [Results] Being compared with the CK (clear water), sucrose solution with low or high concentration will not promote the rooting of Coleus blumei cuttings; illumination will enhance the growth of Coleus blumei cuttings with roots; cutting treatment and management measures will greatly influence the rooting rate of Coleus blumei cuttings. [Conclusions] Sucrose solution will not promote the rooting of Coleus blumei cuttings; illumination will enhance the growth of Coleus blumei cuttings.

Effect of Combinations of Sucrose and Cryoprotectants on the Survival of Catfish Embryos （Pangasidae hypophthamus）

Although cryopreservation of embryos has been used in most terrestrial animals, the application of this technique has not been succeeded for aquatic animals. In this study, the authors investigate the effect of different combinations of sucrose （SUC, C12H22OH） and cryoprotectants （CPAs） on the survival of the catfish embryos （Pangasidae hypophthalmus） at low temperatures （4, 0 and -20 ℃） for short-term storage. For this aim, embryos with somites and optic cups were exposed to different combinations of sucrose with methanol （SUC ＋ MeOH）, 1.2-propylene glycol （SUC ＋ PROH） and ethylene glycol （SUC ＋ EG） at four concentrations ratios： （1） 0.5 M SUC ＋ 0.5 M CPA; （2） 1 M SUC ＋ 0.5 M CPA; （3） 0.5 M SUC ＋ 1 M CPA; （4） 1 M SUC ＋ 1 M CPA for 40 min at 4, 0 and -20 ℃. Embryos kept in water at room temperature （RT）, 4, 0 and -20℃ were used as controls. The survival rate was expressed as a percentage of hatched embryos per total embryos treated. The results showed that the hatching rate declined significantly when embryos were stored in water at 0 ℃ and -20℃. For embryos at 0 ℃ storage, the highest survival rate （87.78%） was obtained with 1 M SUC ＋ 1 M MeOH combination while at -20 ℃, only embryos in the combined treatments of 0.5 M SUC ＋ 1 MEG and 0.5 M SUC ＋ 1 M PROH reached the hatching stage （40% and 83.33%, respectively）. In conclusion, the results showed that the catfish embryos are sensitive to sub-zero temperatures and the combined treatment of 0.5 M sucrose and 1 M propylene glycol can be used to protect catfish embryos from damages caused by low temperature （0 ℃ and -20 ℃）.

Effects on Sucrose Metabolism,Dry Matter Distribution and Fruit Quality of Tomato Under Water Deficit

Four irrigation treatments were designed with 2,4,6 and 8 d intervals to irrigate, respectively. Watering was stopped when the reading of the moisture tension sensor reached zero. The results indicated that glucose and fructose content of tomato's fruit were increased but sucrose content was decreased with fruit growth and development. In different stages, carbohydrate content of tomato fruit in the treatment 3 was the highest, in the treatment 2 was higher, and in the other treatments was the lowest. SS(sucrose synthase)activity was decreased but SPS(sucrose phosphate synthase)activity was increased with development of tomato. SS and SPS activity were increased but acid invertase and neutral invertase activity of ripe stage were decreased under deficit irrigation. Glucose and fructose content were increased in leaves of tomato under water deficit. Soluble sugars, organic acid and the ratio of sugar/acid in tomato fruits were increased and dry matter accumulation of plant was enhanced under water deficit. But the growth of fruits upside the plant and its dry matter accumulation were badly affected under water stress.

Structure and expression analysis of the sucrose synthase gene family in apple

Sucrose synthases(SUS) are a family of enzymes that play pivotal roles in carbon partitioning, sink strength and plant development. A total of 11 SUS genes have been identified in the genome of Malus domestica(Md SUSs), and phylogenetic analysis revealed that the Md SUS genes were divided into three groups, named as SUS I, SUS II and SUS III, respectively. The SUS I and SUS III groups included four homologs each, whereas the SUS II group contained three homologs. SUS genes in the same group showed similar structural characteristics, such as exon number, size and length distribution. After assessing four different tissues, Md SUS1 s and Md SUS2.1 showed the highest expression in fruit, whereas Md SUS2.2/2.3 and Md SUS3 s exhibit the highest expression in shoot tips. Most Md SUSs showed decreased expression during fruit development, similar to SUS enzyme activity, but both Md SUS2.1 and Md SUS1.4 displayed opposite expression profiles. These results suggest that different Md SUS genes might play distinct roles in the sink-source sugar cycle and sugar utilization in apple sink tissues.

Effect of Sodium Ion Concentration on Hydrogen Production from Sucrose by Anaerobic Hydrogen-producing Granular Sludge

This work evaluated the effects of sodium ion concentration, ranging from 0 to 16000mg·L^-1（Na^＋）, on the conversion of sucrose to hydrogen by a high-activity anaerobic hydrogen-producing granular sludge. At the optimum sodium ion concentration [1000-2000mg·L^-1（Na^＋）] for hydrogen production at 37℃, the maximum sucrose degradation rate, the specific hydrogen production yield and the specific hydrogen production rate were 393.6-413.1mg·L^-1.h^-1, 28.04-28.97ml·g^-1, 7.52-7.83ml·g^-1.h^-1, respectively. The specific production yields of propionate, butyrate and valerate decreased with increasing sodium ion concentration, whereas the specific acetate production yield increased, meanwhile the specific production yields of ethanol and caproate were less than 55.3 and 12.6mg·g^-1, respectively. The hybrid fermentation composition gradually developed from acetate, propionate and butyrate to acetate with the increase in sodium ion concentration.

Solid-Liquid Equilibria of D-Glucose,D-Fructose and Sucrose in the Mixture of Ethanol and Water from 273.2 K to 293.2 K

Experimental data on the solubility of D-glucose,D-fructose and sucrose in the mixed solvents com-posed of water and ethanol from 273.2 to 293.2 K were determined.The solubility of D-glucose,D-fructose and sucrose decreased as the ethanol content increased in the mixed solvent.The solubility of D-glucose,D-fructose and sucrose decreased with decreasing equilibrium temperature.The modified UNIQUAC model,S-UNIFAC model and mS-UNIFAC model were applied to predict the solid-liquid equilibria.The prediction results were compared and discussed.Better prediction accuracy was generated using the modified UNIQUAC model.

Significance of a novel sucrose permeability test using serum in the diagnosis of early gastric cancer

AIM： To investigate the usefulness of sucrose permeability test using serum in the diagnosis of gastric diseases, with special reference to early gastric cancer （EGC）. METHODS： A total of 63 subjects, including 11 patients with gastric ulcer, 20 patients with gastric cancer （13, early; 7, advanced） and 32 healthy controls, were studied. Blood and urine samples were collected repeatedly for 5 h before and after the sucrose loading. Sucrose levels were measured by a newly developed RESULTS： Serum sucrose levels started to increase 15 min after loading, and peaked at 60 min in the gastric disease groups. The levels for gastric ulcer, EGC and advanced gastric cancer （AGC） at 60 min were significantly higher than that in the healthy controls （26.9±2.4, 34.4±5.0, and 71.8±15.6 vs 7.9±0.7 mol/L, respectively, P〈0.01）. The cut-off level set at 15.4 mol/L （60 min） offered the best distinction between EGC patients and healthy controls; and the sensitivity and specificity were 92.3% and 93.8%, respectively, while those of the urine method were 76.9% and 93.8%, respectively. CONCLUSIONS： The gastric permeability test using serum is reliable for the detection of EGC, and this test can provide results much earlier than the conventional urine method. This test may offer a useful alternative to more invasive tests for EGC.

Effect of High Temperature on Sucrose Content and Sucrose Cleaving Enzyme Activity in Rice Grain During the Filling Stage

Dynamic changes of sucrose, fructose, glucose contents and differences in activities of sucrose synthase, vacuolar invertase, and cell wall bound invertase in rice grain after flowering stage were studied under natural and high temperatures by using two japonica rice varieties Koshihikari and Sasanishiki. In rice grains, the sucrose synthase activity was higher than that of invertase, which was significantly correlated with starch accumulation rate, indicating that the sucrose synthase played an important role in sucrose degradation and starch synthesis. Under high temperature, the significant increase in grain sucrose content without any increase in fructose and glucose contents, suggested that the high temperature treatment enhanced sucrose accumulation, while diminished sucrose degradation in rice grains. Compared with the control plants, the decrease in activities of sucrose synthase, vacuolar invertase, and cell wall bound invertase with high temperature treated plants indicated that the deceleration of sucrose-degradation was related to the decrease in activities of sucrose synthase and invertase.

Synthesis of insecticidal sucrose esters

Some synthetic sucrose esters （SE） are a relatively new class of insecticidal compounds produced by reacting sugars with fatty acids, which are safe for the environment. Especially, sucrose esters composed of C6-C12 fatty acids have desirable insecticidal properties against many soft-bodied arthropod pests. In our study, sucrose octanoate which has the highest activity against a range of arthropod species was synthesized by a trans-esterification method and proved its insecticidal property. Under the condition of a homogeneous liquid, sucrose octanoate was prepared by reacting ethyl octanoate with sucrose at reduced pressure; the yield was 79.11%. Sucrose octanoate synthesized was identified and its property analyzed by IR, TLC and spectrophotometric analysis. It was shown that the ratio of monoester to polyester in sucrose octanoate was 1.48：1. The insecticidal activity of the synthetic sucrose octanoate was evaluated at a concentration of 4 and 8 mg.mL^-1. The mortality of first-instar larvae ofLymantria dispar from its contact toxicity was 72.5% after 36 hours, the revision insect reduced rate of Aphis glycines reached above 80% at 4 and 8 mg.mL^-1 after being treated for 5 days. Since the SE products are nontoxic to humans and higher animals, fully biodegradable and hydrolyzed to readily metabolizable sucrose and fatty acid, they are not harmful to crops and appear to be good insecticide candidates.

An analytical method for Fe(Ⅱ) and Fe(Ⅲ) determination in pharmaceutical grade iron sucrose complex and sodium ferric gluconate complex

A robust voltammetric method has been developed and validated for the determination of Fe（Ⅱ） and Fe（Ⅲ） in pharmaceutical iron polysaccharidic complexes. Undesirable low molecular weight iron complexes, at concentration about 3% in the pharmaceutical formulation, can be easily determined with good accuracy and precision. This methodology can be proposed as a viable, environmentally sustainable substitute for the conventional Normal Pulse Polarographic method in US Pharmacopeia, with better analytical figures of merit, and reduced Hg consumption. A deeper insight in Fe（Ⅱ） and Fe（Ⅲ） composition can be gained by the combined use of a new potentiometric technique after chemical decomposition of the complex.

Analysis of Sucrose Esters with Long Acyl Chain by Coupling of HPLC-ELSD with ESI-MS System

The analysis of sucrose esters with long acyl chain by improved high performance liquid chromatographic method with evaporative light scattering detection （HPLC-ELSD） and electrospray ionization mass spectrum （ESI-MS） is investigated. The improved HPLC-ELSD method for the separation and quantitation of commercial and synthesized sucrose esters is described. Samples are analyzed by means of a reversed-phase （RP） HPLC using a Hypersil C8 column （250 mm× 4.6 mm, 5 μm particle size） with methanol-tetrahydrofuran （vo）ume ratio of 90 ： 10） and water under gradientcondition as the mobile phase, in which the flow rate is 1.0 ml·min^-1 and the column temperature is set at 40℃. This procedure provides a complete separation and determination ot monoester, diester, triester and higher esters with different acyl chain lengths in each fraction by a single run, in combination with the ESI-MS technology. With this method, it is possible to determine the approximate compositions of monoto polyesters in one analysis and quantitate pure positional isomers precisely using an external standard method. It is found that the method of ESI-MS coupling with HPLC system for the analysis of sucrose esters is straight forward, rapid and inexpensive, and can be readily applied in synthesis, purification and structure studies.

Effects of Neutral Detergent Soluble Fiber and Sucrose Supplementation on Ruminal Fermentation, Microbial Synthesis, and Populations of Ruminal Cellulolytic Bacteria Using the Rumen Simulation Technique (RUSITEC)

We evaluated the effects of neutral detergent soluble fiber （NDSF） and sucrose supplementation on ruminal fermentation, microbial synthesis, and populations of ruminal cellulolytic bacteria using the rumen simulation technique （RUSITEC）. The experiment had a 2x2 factorial design with two dosages of sucrose, low （ca. 0.26 g d-1, low-sucrose） and high （ca. 1.01 g d-1, high-sucrose）, and two dosages of supplied NDSF, low （1.95 g d-1, Iow-NDSF） and high （2.70 g d-1, high-NDSF）. Interactions between NDSF and sucrose were detected for xylanase activity from solid fraction and apparent disappearance of neutral detergent fiber （NDF） and hemicellulose, with the lowest values observed for high-NDSF and high-sucrose treatment. Supplemental NDSF appeared to increase the molar proportion of acetate and reduce that of butyrate; however, the effects of supplemental sucrose on VFA profiles depended upon NDSF amount. There was a NDSFxsucrose interaction for the production of methane. High-NDSF fermenters had lower ammonia-N production, greater daily N flow of solid- associated microbial pellets and total microorganisms, and greater microbial synthesis efficiency compared with low- NDSF fermenters. Supplementation with NDSF resulted in an increase in 16S rDNA copies of Ruminococcusflavefaciens and a reduction in copies of Ruminococcus albus. Supplementation with sucrose tended to increase the 16S rDNA copies ofR. albus from liquid fraction, but did not affect daily total microbial N flow and cellulolytic bacterium populations from solid fraction. These data indicate that the effects of the interaction between NDSF and sugars on ruminal fermentation and fiber digestion should be taken into account in diet formulation. Ruminal fermentation and metabolism of sugars warrant further investigation.

Effects of Increased Night Temperature on Cellulose Synthesis and the Activity of Sucrose Metabolism Enzymes in Cotton Fiber

Temperature is one of the key factors that influence cotton fiber synthesis at the late growth stage of cotton. In this paper, using two early-maturing cotton varieties as experimental materials, night temperature increase was stimulated in the field using far-infrared quartz tubes set in semi-mobile incubators and compared with the normal night temperatures （control） in order to investigate the effects of night temperature on the cotton fiber cellulose synthesis during secondary wall thickening. The results showed that the activity of sucrose synthase （SuSy） and sucrose phosphate synthase （SPS） quickly increased and remained constant during the development of cotton fiber, while the activity of acid invertase （AI） and alkaline invertase （NI） decreased, increased night temperatures prompted the rapid transformation of sugar, and all the available sucrose fully converted into cellulose. With night temperature increasing treatment, an increase in SuSy activity and concentration of sucrose indicate more sucrose converted into UDPG （uridin diphosphate-glucose） during the early and late stages of cotton fiber development. Furthermore, SPS activity and the increased concentration of fructose accelerated fructose degradation and reduced the inhibition of fructose to SuSy; maintaining higher value of allocation proportion of invertase and sucrose during the early development stages of cotton fiber, which was propitious to supply a greater carbon source and energy for cellulose synthesis. Therefore, the minimum temperature in the nightime was a major factor correlated with the activity of sucrose metabolism enzymes in cotton fiber. Consequently, soluble sugar transformation and cellulose accumulation were closely associated with the minimum night temperature.

Variations in Carbohydrate Content and Sucrose-Metabolizing Enzymes in Tomato (<i>Solanum lycopersicum</i>L.) Stamen Parts during Pollen Maturation

The formation of mature and fertile pollen grains, taking place inside the anther, depends on supply of assimilates, in the form of sucrose, provided mainly by the leaves. Data is limited, however, with respect to the understanding of sucrose metabolism in microspores and the supporting tissues. The aims of the present work were to 1) follow the changes in total and relative concentrations of sucrose, glucose, fructose and starch in the stamen parts and microspores up until anthesis, 2) follow the activities of sucrose-metabolism-related enzymes, in the anther walls fraction and microspores of the crop plant tomato. Sucrose was found to be partially cleaved in the filament, decreasing by more than twofold in the anther wall layers and the locular fluid, and to accumulate in the mature pollen grains, constituting 80% of total soluble sugars. Thus, sucrose was both the starting sugar, supporting microspore development, and the main carbohydrate accumulated at the end of the pollen-development program. The major invertase found to be active in both the anther wall layers and in maturing microspores was cell-wall-bound invertase. High fructokinase 2 and sucrose phosphate synthase activities during pollen maturation coincided with sucrose accumulation. The potential importance of sucrose accumulation during pollen dehydration phase and germination is discussed.