外源磷处理对水稻籽粒植酸含量及相关代谢基因表达的影响

利用水稻穗离体培养方法,对不同外源磷浓度下水稻籽粒植酸等磷化物含量的差异及其植酸代谢相关功能基因在灌浆过程中的表达特征进行了探讨。结果表明,水稻籽粒中的植酸、无机磷和总磷含量随外源磷处理浓度上升呈增加趋势,但磷处理对千粒重和单位籽粒中植酸积累量的影响因磷浓度水平而异,高磷处理会导致水稻千粒重和籽粒植酸积累绝对量的显著降低;外源磷处理浓度的上升,不仅会引起水稻籽粒中锌和铁元素含量的显著降低,而且会导致锌、铁营养的生物有效性下降;外源磷处理对水稻籽粒植酸含量的影响与不同磷处理下RINO1基因的相对表达量之间存在较密切关系,中磷浓度(3P)处理会诱导RINO1基因的表达,但高磷浓度(12P)会抑制RINO1基因的表达,RINO1是外源磷浓度处理对水稻籽粒植酸合成代谢过程产生调控作用的一个重要功能基因位点,而IPK2基因与水稻在不同磷浓度处理下的植酸含量变化无直接联系。     

几个籼稻品种的成熟胚愈伤组织植株再生体系的建立

组织培养技术在作物改良上的成功应用需要合适的植株再生体系。本试验以7个籼稻成熟胚为材料，通过优化激素配比，建立适合于水稻遗传转化的高频植株再生体系。研究结果表明，NB 2mg／L2，4-D适合于供试品种的成熟胚愈伤组织的诱导，诱导率达90％以上；在分化培养基中添加3．0-3．5mg／L KT，0．5～1．0mg／L NAA和5．0mg／L ABA的激素配比，明恢81、N175、航1号的最高分化率分别达72．7％、80．0％和78．0％；移栽成活95％以上。     

Glutelin is partially degraded in globulin-less mutants of rice (Oryza sativa L.)

Multigenic glutelins and monogenic globulin are major storage proteins accumulating in vacuole-derived protein body (PB-II) of rice (Oryza sativa L.) seeds. Because their interplay in PB-II formation was scarcely known, the effect of globulin-less mutation on glutelin accumulation was investigated. In globulin-less mutants, no phenotypic defect was found in seed and plant growth, while PB-II was deformed and apparent glutelin composition was changed, producing new glutelin α polypeptides X1–X5. 2D-PAGE of different combinations of globulin-less and glutelin subunit mutations suggested that the X1/X2, X3, and X4/X5 were derived from glutelin GluB1/GluB2/GluB4, GluA3, and GluA1/GluA2 subunits, respectively. Western blot with glutelin GluB4 subunit-specific and its variable region discriminable antibodies indicated at least in part the new spots X1/X2 are partially degraded products of GluB4 α polypeptides by the removal of 2–39 residues from C-terminus. Time course experiments with maturing seeds indicated the partial degradation of GluB4 occurred earlier (from 7 days after flowering) and higher than that of GluA1/GluA2. Considering the above results together with the fact that globulin accumulates at the periphery of PB-II and its absence produces deformed PB-II, globulin protects glutelins from proteinase digestion and thereby facilitates stable glutelin accumulation.     

不同生态环境下水稻穗部性状QTL鉴定

【目的】发掘与产量相关的穗粒性状QTL对进一步克隆和利用高产基因具有重要意义。【方法】以超级粳稻龙稻5号和典型高产籼稻中优早8号杂交衍生的重组自交系群体为试材,在4种环境下对穗部性状进行比较和QTL分析。【结果】共检测到63个穗部性状QTL,分布于除第9染色体外的11条染色体上。在4个环境下分别检测到27、27、18和35个QTL。其中,16个QTL能在2个环境下被检测到,12个在3个以上环境下稳定表达,分别占QTL总数的25.40%和19.05%;第1、3、4和5染色体的多效QTL簇能在不同环境下稳定表达,对穗部性状具有明显的调控作用。【结论】第3染色体STS3.3-STS3.6区间的qSNP3、第4染色体RM5688-RM1359区间的qSNP4.1是2个新的稳定表达的多效性QTL簇。此外,上位性效应是调控穗部性状的重要组分。     

Ammonia Emission from Leaves of Different Rice (Oryza sativa L.) Cultivars

Abstract

NH₃ emission from leaves of three rice (Oryza sativa L.) cultivars, Akenohoshi, Shirobeniya and Kasalath, was examined using a simple open chamber system.　In the three cultivars, NH₃ emission rate (AER) and NH₄⁺ content of leaves decreased with decreasing NH₄⁺ concentration in the root medium, but these values differed significantly with the cultivar. In the daytime, AER, NH₄⁺ content and glutamine synthetase (GS) activity in leaves changed similarly with maximum values around midday. Akenohoshi showed significantly lower AER and NH₄⁺ content but higher GS activity than Kasalath. The difference in AER among the rice cultivars may be related to the activity of GS involved in photorespiratory NH₃ recycling. Akenohoshi can be a breeding material useful for improving N recycling.     

一份水稻OsWOX3B基因敲除突变体的鉴定

[目的]水稻OsWOX3B基因调控叶片形态和表皮毛发育,根据表型被命名为LSY1、DEP、NUDA和GLR1等.深入了解OsWOX3B基因对水稻发育调控的功能具有重要意义.[方法]利用CRISPR/Cas9基因编辑技术对籼稻品种R401的OsWOX3B进行基因敲除.对所获材料进行突变位点分析和表型分析,同时进行相关基因...     

Salinity-Induced Ultrastructural Alterations in Leaf Cells of Rice (Oryza sativa L.)

Summary

High concentrations of NaCl significantly reduced the fresh and dry weights and lengths of roots and shoots. NaCl exhibited a more rapid effect in water culture than in soil culture. In both water and solid cultures, root growth was suppressed more severely than shoot growth. Electron microscopic studies revealed that NaCl caused swelling of thylakoids, accumulation of starch grains and lipid droplets, distortion of grana stacking, increase in the size and number of plastoglobuli and vesiculation of cellular membrane. Mitochondria became deficient in cristae, swelled and the matrix appeared pale in salt-treated plants as compared with control plants. Disappearance of nucleolus and nuclear chromatin and destruction of vascular tissues were occasionally observed in salt-treated plants.     

Effects of Exogenous Glycinebetaine on Growth and Ultrastructure of Salt-Stressed Rice Seedlings (Oryza sativa L.)

Abstract

The effects of exogenously applied glycinebetaine on the salt-stress-induced inhibition of growth and ultrastructural damages in rice seedlings were investigated. Glycinebetaine was not effective in alleviating the NaCl-induced inhibition of root growth and rather enhanced the NaCl-induced inhibition. However, it was found to alleviate the inhibition of shoot growth induced by NaCl stress. Concentrations of Na were higher in salt-stressed plants than in unstressed plants. Stressed plants receiving glycinebetaine had a significantly lower Na and higher K concentrations in the shoots than the plants grown without application of glycinebetaine. Salinity induced ultrastructural damages in leaf such as swelling of thylakoids, disintegration of grana stacking and intergranal lamellae and destruction of mitochondria (deficiency of cristae, swelling and vacuolation). Such damages were largely prevented by pretreatment with glycinebetaine resulting in greening of the plants. In roots, the epidermis, cortex and root cap were more sensitive to salt stress than the meristem and stele. The most frequently observed ultrastructural alteration due to NaCl salinity was the formation of many large vacuoles in the root tip and root cap cells. The number of mitochondria was increased and they were aggregated in the cytoplasm of the root tip and root cap cells by treatment with NaCl or NaCl plus glycinebetaine. Glycinebetaine could not prevent the NaCl-induced ultrastructural damages in root cells. The effects of glycinebetaine to mitigate the ultrastructural damages in the chloroplast and mitochondria induced by NaCl might be due to the production of many vacuoles in root cells which may act to store Na and decrease its accumulation in the shoot.     

利用同工酶标记水稻亲本遗传差异及其在杂交水稻育种中的利用

利用淀粉凝胶和聚丙烯酰胺凝胶电泳显示的同工酶差异，分析17个杂交水稻亲本、3个新株型株系和22个光壳稻、爪哇稻品种的遗传差异，研究光壳稻和爪哇稻及其与温带粳稻之间的关系，探索同工酶标记水稻亲本遗传差异在杂交稻育种中利用的可能性。在本研究中，8个同工酶18个多态性位点至少在2个基因型间存在差异。每个具有多态性的酶谱带分别以1和0记录存在与否，由同工酶数据计算的Nei’s遗传距离创建聚类树状图。聚类分析结果表明，籼稻和粳稻容易被分开，普通粳稻与光壳稻、爪哇稻混合聚在一起；光壳稻与爪哇稻之间的遗传距离要比它们与普通粳稻之间的遗传距离小。利用光壳稻、爪哇稻选育不同生态群方向的恢复系和不育系，已配组育成了强优势的杂交稻组合。     

Grain Protein Content of Interspecific Progenies Derivedfrom the Cross of African Rice (Oryza glaberrima Steud.) and Asian Rice (Oryza sativa L.)

Abstract

The protein contents of the grain of 50 interspecific progenies developed from the cross between WAB56-104, an Oryza sativa variety, and CG 14, an Oryza glaberrima line, were investigated. In contrast to the higher protein content of O. glaberrima than O. sativa on the average, the protein content of CG 14 was always lower than that of WAB56-104. However, judging from the average of three seasons, 72% of the interspecific progenies had a higher protein content than the mid-parent and 50% of them had a higher protein content than WAB56-104. Although the actual values of protein content of the interspecific progenies were significantly different among the seasons, a highly significant correlation was always observed in protein content between any two of the three seasons. Protein content therefore was considered character of each interspecific progeny though it was also affected by environment. A significant correlation was not observed between paddy yield and protein content in any season; several interspecific progenies showed higher protein content and paddy yield than the mid-parents. A low paddy yield is likely to be associated with high protein content through physiological regulation without a genetic linkage between the two traits. However, the results suggest that the transgressive segregation of protein content observed in the interspecific progenies is attributed not to this physiological regulation but to a certain mechanism to concentrate protein in grains with a genetic background.     

Effects of Salinity Stress on the Seminal Root Tip Ultrastructures of Rice Seedlings (Oryza sativa L.)

Abstract

Growth and structural changes in the seminal root tip of rice seedlings (Oryza sativa L. cv. Nipponbare) in response to NaCl salinity were studied. Seedlings were grown in agar medium with 0, 0.1, 0.3, 1.0, 2.0 and 3.0% NaCl(agar culture), and in water with 0, 0.01, 0.03, 0.06 and 0.1% NaCl (water culture). Seedling growth was significantly suppressed by higher concentrations of NaCl. The effect of NaCl appeared faster in water culture than in agar culture. In both agar and water cultures, root growth was markedly suppressed over shoot growth. Under saline conditions, epidermis, cortex and root cap cells appear to be damaged to a greater extent than the meristem and stelar cells. The most notable ultrastructural change in response to salinity was the development and increment of vacuoles, which seem to provide a space for accumulation of excess ions. Many electron dense deposits were observed in the larger vacuoles of the epidermal and cortical cells. Under saline conditions, cell wall thickening of the epidermis, an increase in endoplasmic reticulum, myelin figures, less compact Golgi bodies and inhibited production of Golgi vesicles were also observed.     

根表铁胶膜对镉污染土壤水稻吸镉量的影响(英文)

通过采用镉污染的土壤—河砂—营养液联合培养的方法,研究了在水稻分蘖期施铁对水稻根表铁胶膜中铁及铁胶膜吸附镉的影响。设四个亚铁(Fe~(2+))处理水平分别为:0、30、50、70mg/L,研究施铁浓度与水稻根表铁氧化物胶膜的数量和吸附镉量之间的关系。结果表明,施铁处理的铁胶膜中铁的含量比不施铁(0处理)的高,但在其他三种处理 (30、 50、70mg/L)中,随施铁浓度的升高而降低。另外,施铁浓度与铁胶膜的数量呈正相关,所以,铁胶膜吸附镉与施铁浓度呈正相关。在水稻的另外三个时期:拔节、孕穗、灌浆期,对该问题将作进一步研究。     

水稻显性脆秆突变体Bc18的鉴定和基因定位

从三交组合Ⅱ-32B//协青早B/Dular的F₂群体中获得了1个脆性突变体,整个植株表现全生育期脆性。根据该突变体的表型,将其命名为Bc18(Brittle culm 18)。为了更好地鉴定该突变体,用正常茎秆强度品种中9B作轮回亲本与Bc18杂交,创制了Bc18脆秆近等基因系中脆B和中9B。表型鉴定显示,突变体Bc18在生育期、株高、单株穗数、每穗粒数、结实率和千粒重等主要农艺和产量性状上与野生型中9B 无显著差别,但茎、叶的机械强度分别下降了70.70%和47.16%。细胞壁组分分析表明,突变体Bc18茎、叶的纤维素和木质素含量与野生型中9B 无显著差异,但半纤维素含量分别提高了31.84%和17.35%。6个杂交组合F₂和12个回交BC₁F₁群体的遗传分析证明Bc18 脆性突变由单显性基因控制。采用图位克隆技术,构建了Bc18/02428和Bc18/9311的F₂定位群体,并利用网上公布的SSR标记和新设计的InDel标记,最终将Bc18基因定位在第1染色体长臂端InDel标记PBC22与PBC33之间约154 kb的区间内。     

The effects of nitrogen uptake before and after heading on grain protein content and the occurrence of basal- and back-white grains in rice (Oryza sativa L.)

Chalky rice (Oryza sativa L.) grains are induced by high temperature during the grain-filling period. Plant nitrogen status also affects the occurrence of basal- and back-white grains (BBWG). The objective of this study was to elucidate the relations between nitrogen availability per spikelet during the grain-filling period (N_GF) and each of the percentage of BBWG and grain protein content (GPC). We further compared the effect of the components of N_GF determined before heading (N_BH) and after heading (N_AH) on BBWG and GPC. We grew the rice cultivar ‘Koshihikari’ in pots in 2012 and 2013, and top-dressed nitrogen at the panicle formation and heading stages, under two (2012) or three (2013) temperature regimes during the grain-filling period. GPC was explained well by N_GF, but BBWG was not. BBWG was best explained in a multiple-regression equation by mean air temperature after heading and by N_BH and N_AH. The partial correlation coefficients for N_BH were 1.6 and 3.0 times those for N_AH in 2012 and 2013, respectively. On the other hand, in a multiple-regression equation for GPC, the partial correlation coefficients for N_BH were 0.91 and 0.71 times those for N_AH in 2012 and 2013, respectively. These results suggest that rice grains are most sensitive to plant nitrogen status before heading for BBWG but after heading for GPC, and that there is an optimal timing for nitrogen top-dressing that would maximize the reduction in BBWG per unit increment of GPC.     

不同土壤水分含量对水稻水分利用特征的影响

 采用控制土壤水分含量的盆栽实验,研究了土壤水分含量对水稻水分利用特性的影响。结果表明,常规水作累积耗水量显著高于覆膜未淹水处理,但稍低于覆膜淹水处理;覆膜轻度水分胁迫或无胁迫处理不仅能够维持和提高产量,水分利用效率也有所提高。随着土壤水分含量的降低,全生育期水稻累积耗水量、各生育期耗水量及耗水强度逐渐降低,且田间持水量与全生育期累积耗水量呈极显著二次曲线相关。无水分胁迫覆膜处理下拔节孕穗期耗水量及模比系数高于其他生育期,其他处理耗水量和模比系数在乳熟期最高。随着土壤水分含量降低,抽穗开花期前各生育期水稻耗水模比系数有降低趋势,其后则有升高趋势;耗水强度下降;有效穗数和实粒数减少,产量逐渐降低,水分生产率先上升后下降。水稻产量与水分利用率具有显著二次曲线相关性。     

水稻花粉发育过程及其分期

以籼稻品种IR36为材料,采用塑料半薄切片技术、新鲜花药整体观察及游离的雄性细胞观察方法,对水稻花粉发育全过程及其药壁组织的情况进行了系统的研究,初步将这一过程划分为8个时期,即小孢子母细胞形成期、小孢子母细胞减数分裂期、小孢子早期、小孢子中期、小孢子晚期、二胞花粉早期、二胞花粉晚期和成熟花粉期。并证实了花粉自然发育过程中不存在收缩期。在这一发育过程中,绒毡层出现3种明显不同的发育形态,这些形态特点对于判断花粉发育阶段具有重要的参考价值及辅助作用。     

Molecular Cloning and Characterization of Citrate Synthase Gene in Rice （ Oryza sativa）

The full-length OsCS encoding citrate synthase was isolated from rice （Oryza sativa L. subsp, japonica）, OsCS is 1477-bp long and encodes a 474 amino acid polypeptide, Its putative protein sequence is highly identical to Daucus carota, Nicotiana tabacum Beta vulgaris subsp., Arabidopsis thaliana, and Citrus junos （〉70%）. The deduced amino-terminal sequence of OsCS showes characteristics of mitochondrial targeting signal. Southern blot analysis using ORF of the OsCS as the probe indicated that this gene exists in multiple copies in rice genome. The band with predicated size of 82 kD was detected by Western blot after being induced by 0,4 mmol/L IPTG.     

Influence of high temperature during filling period on grain phytic acid and its relation to spikelet sterility and grain weight in non-lethal low phytic acid mutations in rice

Low phytic acid (lpa) crop is considered as an effective strategy to improve crop nutrition. However, the inferior agronomic performance of lpa crops and their environmental growth adaptation have not yet been fully understood. Three rice lpa lines and their corresponding wild-types were used to compare their differences in grain phytic acid (PA) in response to high temperature (HT) and its relation to spikelet sterility and grain weight at a controlled temperature at the filling stage. Results showed that HT caused an increase in grain PA and inorganic phosphate contents, with more substantial increase of PA content for lpa lines compared with corresponding wild-types. This increase in PA content in high temperature-ripened grains was not simply attributed to the reduction in grain weight and relatively enhanced proportion of aleurone-layer fraction to whole grains. Significant increase in PA contents was also detected in milled rice. Moreover, spikelet sterility and grain plumpness of lpa lines were more susceptible to HT stress than those of wild-types. Exogenous PA spraying with an appropriate concentration could increase grain PA content, but it had only a slight contribution to the enhancement of heat-tolerance and injury alleviation for rice exposed to stressful HT.