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Tatsuya Hirano Takayuki Higuchi Minako Hirano Yu Sugimura Hiroyasu Michiyama 《Plant Production Science》2016,19(2):291-299
To identify mechanisms of starch degradation in rice leaf sheaths at the post-heading stage, we investigated the function of OsBAM2 and OsBAM3, which encode plastid-targeted active β-amylase isoforms, in starch remobilization in leaf sheaths. The starch content in the second leaf sheaths below the flag leaf (the third leaf sheaths) peaked at the flag leaf emergence stage and gradually decreased until 15 days after heading. The mRNA levels of OsBAM2 and OsBAM3 in the third leaf sheaths increased from the flag leaf emergence stage to the heading stage when the starch content began to decrease. However, these mRNA levels did not always remain high during post-heading. Overexpression of OsBAM2 or OsBAM3 markedly repressed starch accumulation in the third leaf sheaths, showing that OsBAM2 and OsBAM3 function in starch degradation in rice leaf sheaths. In contrast, no significant differences in starch content in the third leaf sheaths were detected between knockdown plants of OsBAM2 or OsBAM3 and non-transgenic wild-type plants. Our results suggest that reduced expression of the individual genes, OsBAM2 or OsBAM3, does not result in excess accumulation of starch in the leaf sheaths, probably because of the complementary function of another gene or the action of other genes encoding starch-degrading . 相似文献
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《Plant Production Science》2013,16(5):546-552
AbstractIn rice plant, carbohydrates accumulated in leaf sheaths before heading are translocated to grain and affect yield formation greatly. To clarify the intrinsic mechanism of carbohydrate metabolism in the leaf sheath, we investigated the temporal and spatial variations of carbohydrate metabolism in the third leaf sheath counted from the top and their varietal differences. The results revealed that the amount of carbohydrate decreased from the base to the tip of the leaf sheath, irrespective of variety and developmental stage. However, the proportion of starch content in the basal one-fifth of the leaf sheath to that in the whole sheath varied from 35% to 60% with the variety. Comparing the activities of enzymes related to starch metabolism at the base, middle and tip of the leaf sheath in IR65598-112-2 (New plant type) with those in Nipponbare, the activities of ADP-glucose pyrophosphorylase, branching enzyme and granule-bound starch synthase (GBSS) showed varietal differences. Particularly, the activity of GBSS may play an important role in the varietal difference in spatial variation of starch content in the leaf sheath. In IR65598-112-2, the sucrose content in the leaf sheath was extremely high, suggesting that sucrose may be one of the carbohydrate reserves in this line. 相似文献
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《Plant Production Science》2013,16(2):122-130
AbstractThe effects of the amount of nitrogen fertilizer on the starch metabolism of rice leaf sheath during the heading period in the japonica rice variety, cv. Nipponbare were compared with those in the indica varieties, cv. Tetep and Johna. The rice plants were grown under a low- (similar to the standard nitrogen level in paddy field) or high-nitrogen condition, and the starch content of the second leaf sheaths below the flag leaf was analyzed from the second leaf stage (growth stage 1) until 21 days after the heading (growth stage 7). The starch content of the plants grown under the high-nitrogen condition at the heading stage (growth stage 4) was lower than that under a low-nitrogen condition in all the varieties. The decrease in the activity of starch branching enzyme (SBE) was considered to be important for the repression of starch accumulation under a high-nitrogen condition. Under the high-nitrogen condition, Nipponbare accumulated more starch in the second leaf sheath than indica varieties at the heading stage. However, the phenomenon could not be accounted for by the activities of AGPase and SBE. Semi-quantitative RT-PCR analysis suggested that the lower activities of SBE in the second leaf sheath under the high-nitrogen condition may be due to, at least in part, the decrease in the expression level of RBE4. 相似文献
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以叶片不同气孔密度(高、中和低气孔密度)水稻品系为试验材料,在齐穗期研究水稻剑叶光合特性、糖分含量和蔗糖代谢酶活性。结果表明,水稻叶片中蔗糖含量、蔗糖磷酸合成酶活性与气孔密度呈极显著正相关;蔗糖合成酶活性与气孔密度呈显著正相关。高气孔密度水稻叶片Rubisco活性、净光合速率、蔗糖含量、蔗糖磷酸合成酶和蔗糖合成酶活性显著高于低气孔密度水稻;不同叶片气孔密度与中性转化酶呈显著负相关。研究认为,气孔密度增加提高了水稻叶片光合效率,促进了蔗糖积累及蔗糖代谢酶活性提高,有利于更多光合产物——蔗糖向籽粒转运。 相似文献
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Six rice varieties, PR120, PR116, Feng Ai Zan, PR115, PAU201 and Punjab Mehak 1 were raised under aerobic and transplanting conditions to assess the effects of planting conditions on sucrose metabolising enzymes in relation to the transformation of free sugars to starch and protein in flag leaves and grains. Activities of sucrose synthase, sucrose phosphate synthase and acid invertase increased till flowering stage in leaves and mid-milky stage(14 d after flowering) in grains and thereafter declined in concomitant with the contents of reducing sugar. Under aerobic conditions, the activities of acid invertase and sucrose synthase(cleavage) significantly decreased in conjunction with the decrease in non-reducing sugars and starch content in all the varieties. Disruption of starch biosynthesis under the influence of aerobic conditions in both leaves and grains and the higher build up of sugars possibly resulted in their favoured utilization in nitrogen metabolism. Feng Ai Zan, PR115 and PR120 maintained higher levels of sucrose synthase enzymes in grains and leaves and contents of metabolites(amino acid, protein and non-reducing sugar) under aerobic conditions, while PR116, Punjab Mehak 1 and PAU201 performed better under transplanting conditions, thus showing their adaptation to environmental stress. Yield gap between aerobic and transplanting rice is attributed primarily to the difference in sink activity and strength. Overall, it appear that up-regulation of sucrose synthase(synthesis) and sucrose phosphate synthase under aerobic conditions might be responsible in enhancing growth and productivity of rice varieties. 相似文献
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《Plant Production Science》2013,16(3):160-165
AbstractSeveral types of water soluble carbohydrates (WSG) were traced into plant parts of a winter wheat (Triticum aestivum L.) cultivar from heading to physiological maturity. Field grown plants were harvested at intervals of a few days and divided into grain, chaff, leaf blades, leaf sheaths, rachis + peduncle and culm internodes. Leaf blades and sheath showed the peak of WSC contents at about anthesis. Culm internodes accumulated fructan and sucrose during the early grain-filling phase, from a week after anthesis until the milk-ripe stage, then remobilized them during late and final grain filling phases, from the milk-ripe stage until maturity. The amount of sucrose known as short-term storage WSC was higher than fructan known as long-term storage WSC in each internode throughout the grain-filling phase. Chaff showed a large amount of fructan and fructose before anthesis, although it did very little sucrose. A pattern of sucrose accumulation in chaff was very different from that of fructan, unlike the other parts. These patterns of changes in WSC contents in plant organs roughly corresponded with four grain-filling phases, the initial, early, late and final phases. 相似文献
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《Plant Production Science》2013,16(2):224-232
AbstractIn rice (Oryza sativa L.), the maintenance of high photosynthetic rate of flag leaves and the carbon remobilization from leaf sheaths after heading is a critical physiological component affecting the yield. To clarify the genetic basis of RuBisCO content of the flag leaf, a major determinant of photosynthetic rate, and non-structural carbohydrate (NSC) concentration in the third leaf sheath at heading, we carried out quantitative trait loci (QTL) analysis with 39 Koshihikari/Kasalath chromosome segment substitution lines (CSSLs) and backcross progeny F2 population derived from target CSSL holding the QTL/Koshihikari in the field. QTLs for RuBisCO content and NSC concentration at heading were detected between R2447-C1286 and R2447-R716 on chromosome 10, respectively, by comparing Koshihikari with four CSSLs for chromosome 10 (SL-229, -230, -231 and -232). The progeny QTL for RuBisCO content and for NSC concentration at heading qRCH-10 and qNSCLSH-10-1, respectively, were detected at similar marker intervals between RM8201 and RM5708. In addition, QTLs for RuBisCO content at 14 d after heading, qRCAH-10-1 and qRCAH-10-2, were detected in regions different from that of qRCH-10. No QTL for NSC concentration at 14 d after heading was detected between RM8201 and R716, the region analyzed in this study. The QTLs qRCH-10 and qRCAH-10-1 for RuBisCO content would have additive effects. These QTLs for RuBisCO content and NSC concentration newly found using CSSLs and their backcross progeny F2 population should be useful for better understanding the genetic basis of source and temporary-sink functions in rice and for genetic improvement of Koshihikari in terms of their functions. 相似文献
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【目的】探明不同氮利用率水稻品种的氮素积累与转运特征及其机制。【方法】2个氮高效品种(武运粳30号和连粳7号)和2个氮低效品种(扬粳4038和宁粳1号)种植于大田,设置2个施氮量：全生育期不施氮(0N)和全生育期施氮180kg/hm2(180N),比较分析了不同氮利用率粳稻品种干物质生产、氮素积累与转运差异及其机制。【结果】与氮低效品种相比,氮高效品种具有较高的产量、氮肥利用率、总颖花量和结实率,较高的花前干物质转运量和花后干物质积累量,分蘖至穗分化始期和抽穗至成熟期较高的净同化率和作物生长率,抽穗期较高的糖花比,灌浆期较高的籽粒库活性、籽粒中脱落酸与1-氨基环丙烷-1-羧酸含量的比值和茎鞘中较高的非结构性碳水化合物的转运和蔗糖合成相关酶活性以及蔗糖转运蛋白基因的表达量,抽穗后较高的氮转运、氮素吸收量,灌浆期较高的比叶氮含量、叶片中细胞分裂素含量、氮代谢酶活性以及氮素转运相关基因的表达量。【结论】氮高效品种穗分化前和抽穗后较高的物质生产效率以及灌浆期较高的碳氮转运与积累是产量和氮肥利用率协同提高的重要机制。 相似文献
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为了探明灌溉对淀粉积累及其相关酶活性的影响规律,在大田条件下,以弱筋小麦豫麦50为材料,研究了三种灌溉方式(W1:拔节期灌水一次;W2:拔节期和孕穗期各灌水一次;W3:拔节期、孕穗期和灌浆期各灌水一次.每次灌水定额750 m3/ha)下弱筋小麦淀粉及其相关酶活性的变化规律.结果表明,弱筋小麦灌浆中后期和成熟期籽粒直链淀粉、支链淀粉、总淀粉积累速率均表现为W3>W2>W1.成孰期籽粒淀粉支/直比例表现为W3＞W2＞W1.成熟期籽粒淀粉支/直比例表现为W3＜W2＜W1.孕穗期和灌浆期增加灌水提高了灌浆中后期旗叶和籽粒中蔗糖含量、蔗糖合成酶(SS)活性、蔗糖磷酸合成酶（SPS）活性,提高了灌泺中后期籽粒中可溶性淀粉合成酶(SSS)活性和束缚态淀粉合成酶(GBSS)活性.说明增加灌水使弱筋小麦旗叶蔗糖合成能力强,促进源器官蔗糖向库中运输,保证籽粒库中糖源的充分供应,有利于籽粒淀粉的合成和积累. 相似文献
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ABSTRACTRice (Oryza sativa L.) is one of the most important staple foods in the world, however most improved rice varieties are susceptible to drought stress. A two-year study was conducted to explore the effects of various drought stresses and subsequent recovery on the accumulation and degradation of proline, total soluble sugar and starch in different rice varieties at vegetative stage. The results showed that relative water content in the leaves and sheaths of rice varieties significantly decreased under drought stresses, but not at the same rate. Under control and drought conditions, the water content in sheaths was higher than that in leaves. Interestingly, under severe drought stress in 2015, the leaf water content was higher than the sheath water content. The water distribution between leaves and sheaths might be a response of plants to protect leaf system from devastation by drought. Proline was highly accumulated under drought stress but rapidly decreased after re-watering. The drought tolerant variety DA8 expressed higher ability in accumulation of proline than susceptible varieties. In general, total soluble sugar and starch contents in leaves and sheaths of varieties decreased under drought stress conditions. Total soluble sugar and starch content of DA8 were less affected than other varieties under drought conditions. Our study indicated that metabolisms of total soluble sugar and starch in rice were affected by both environmental conditions and characteristics of varieties. Proline accumulation ability of varieties can be used as a useful indicator for drought tolerant potential in rice breeding for water-limited environments. 相似文献
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以玉米自交系B73为试验材料,研究施用外源乙烯之后对胚乳内淀粉合成的影响。结果表明,在玉米10展叶时期施用400 mg/L的乙烯利水溶液显著降低玉米百粒重和淀粉含量。淀粉合成相关酶活性测定结果表明,处理组中ADP葡萄糖焦磷酸化酶、可溶性淀粉合成酶、淀粉分支酶、蔗糖合成酶的活性均显著下降。淀粉合成相关基因表达量分析结果表明,处理组中ADP葡萄糖焦磷酸化酶基因ZmSH2、可溶性淀粉合成酶基因ZmSS1、蔗糖合成酶的基因ZmSH1表达量低于对照组。由此推测,外源乙烯通过调控淀粉合成相关基因的表达与酶的活性影响玉米胚乳内淀粉的合成。 相似文献
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为研究小麦花后旗叶和籽粒中内源激素、蔗糖含量及籽粒中淀粉积累的动态变化,以弱筋小麦宁麦9号为供试材料在两种施肥处理条件下分析了花后内源激素和蔗糖含量变化与籽粒淀粉合成的关系.结果表明,氮肥后移的处理旗叶中ZRs、iPAs含量的增加及ABA含量的减少,有利于光合产物的合成;蔗糖含量较高,为籽粒合成淀粉提供了充足的碳源物质.籽粒中淀粉及其组分积累量灌浆期呈不断上升的趋势,积累速率呈单峰曲线,直、支链淀粉和总淀粉积累速率峰值期均在花后21～28 d,氮肥后移表现为增加趋势.相关分析表明,籽粒中内源激素ABA与蔗糖含量呈极显著负相关,GA1/3/ABA与蔗糖含量呈极显著正相关,IAA、GA1/3与淀粉积累速率呈极显著正相关.通径分析表明,籽粒中内源激素IAA对淀粉积累速率有极显著促进作用,直接通径系数达0.9627**,GA1/3主要是通过提高IAA含量间接促进籽粒中淀粉的积累,说明适当提高IAA含量有利于促进籽粒淀粉的积累. 相似文献
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杂交水稻始穗期氮钾营养对剑叶生理特性的影响 总被引：13，自引：0，他引：13
采用盆栽试验研究了杂交水稻汕优63在施基肥的基础上，始穗期供给 NK营养对剑叶生理特性的影响。施用NK，可促进剑叶叶绿素含量、光合速率、蔗糖磷酸合成酶(SPS)、过氧化物酶(POX)、超氧物歧化酶(SOD)、硝酸还原酶(NR)活性提高，呼吸速率下降，增加剑叶的可溶性糖和可溶性蛋白含量及根系活力，加速14C同化物从剑叶的输出，提高14C同化物在稻穗的分布积累及输入积(IAP)。讨论了始穗期共施NK营养提高结实率、谷粒充实度及稻谷产量的良好效果 相似文献
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《Plant Production Science》2013,16(1):9-16
Abstract The objective of this study was to elucidate the roles of sugar in the formation of root systems. Several parts of theseminal root were investigated to determine their sucrose, glucose and fructose contents, and the activity and the in situ localization of the activities of two kinds of metabolic enzymes, invertase and sucrose synthase, whichhydrolyze sucrose. The sucrose, glucose and fructose concentrations in the 0-1 cm section from the root apex were three to five times those in the other sections. The invertase and sucrose synthase activities were also higher in the apical section. The in situ localization of invertase activity was detected in the cell elongation zone of the seminal root using histochemical method. The sucrose synthase activity was detected in the cell elongation zone of the seminal root and the root apices of lateral roots. These results suggested that sucrose is transported to the root elongation zone and the surrounding tissue of the lateral root primordia, and is cleaved into glucose, fructose, and UDP-glucose by invertase or sucrose synthase. This suggested that sucrose contributes to root formation by serving as the energy source, the carbon source for cell wall synthesis, and as a compatible solute for cell elongation. 相似文献
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灌浆成熟期粳稻抗倒伏性和茎鞘化学成分含量的动态变化 总被引：5，自引：0，他引：5
分析了不同抗倒类型的粳稻品种灌浆成熟过程中茎鞘抗倒伏性和化学成分含量的动态变化。结果表明,不同抗倒类型品种茎鞘的钾、硅和可溶性糖等总量差异很大,与钾和可溶性糖总量相比,硅总量的差异较大。随着籽粒灌浆进程,不同抗倒类型品种的茎秆物理强度和最大承载量均逐渐变小,到成熟期为最小,尤其是茎秆物理强度到蜡熟期开始迅速变小,但茎的钾、硅含量和总量及叶鞘的硅含量逐渐增加,出现沉积现象,而叶鞘的钾含量和总量及硅总量逐渐减少,呈输出迹象。除齐穗期茎的钾总量外,灌浆不同时期茎秆物理强度与茎的钾总量和硅总量均呈极显著正相关;茎秆物理强度与齐穗期和乳熟期茎的可溶性糖总量,与齐穗期叶鞘的硅总量和可溶性糖总量,与齐穗期和乳熟期的钾总量呈极显著或显著正相关,灌浆各时期穗部最大承载量与茎秆物理强度均呈极显著正相关。说明提高灌浆前期的茎鞘可溶性糖总量,以及通过追施硅肥增加植株硅总量有利于提高水稻抗倒伏能力。 相似文献
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土壤水分对水稻光合速率与物质运转的影响 总被引：29，自引：3，他引：29
以6个中熟水、陆稻品种为材料，研究了在不同土壤水分状况下水稻光合速率与物质运转的特点。叶片光合速率随土水势的下降而减小，抗旱性品种减小的幅度小于抗旱性较差的品种。长期低土壤水分处理后，群体光合能力的下降主要是由于叶面积的减小。低土壤水分处理导致叶片中蔗糖和总可溶性糖含[CM(45*2]量的增加，淀粉含量的减少。淀粉/可溶性糖、淀粉/蔗糖与相对产量(处理/对照)呈极显著正相关(r=0.9854、 r=0.9412)。低土壤水分处理下，抽穗期茎鞘中可用性糖(可溶性糖+淀粉)累积量减少，抽穗后运转率增加，抗旱性品种的相对累积量(处理/对照)高于抗旱性较差的品种，但运转率的大小与品种的抗旱性无明显联系。 相似文献
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氮素用量对春玉米穗位叶蔗糖合成关键酶活性的影响 总被引：2，自引：1，他引：1
试验以高淀粉玉米四单19、普通玉米东农250、优质蛋白玉米丰禾10为材料,研究氮素用量对春玉米穗位叶蔗糖代谢的影响,揭示蔗糖合成过程中蔗糖合成酶(SS)和蔗糖磷酸合成酶(SPS)的调节作用。结果表明：氮素用量适当有利于提高玉米穗位叶蔗糖含量、蔗糖合成酶活性和蔗糖磷酸合成酶活性,证实了蔗糖合成酶和蔗糖磷酸合成酶能促进春玉米叶片蔗糖积累。 相似文献