NRRB在水稻应答高盐和干旱胁迫中的功能解析

为研究NRRB在水稻抗逆反应中的作用,通过重叠延伸PCR扩增NRRB基因编码区,构建超量表达载体,并转化水稻愈伤组织获得超量表达转基因水稻植株。鉴定结果表明,该基因已被整合到水稻基因组中,并实现超量表达;同时构建了抑制表达载体,获得转基因株系,PCR检测结果证实NRRB基因在转基因水稻中受到明显抑制。对T1代转基因植株进行抗旱性、耐盐性分析,结果显示,超量表达NRRB基因增强了转基因水稻对干旱的抗性,抑制表达NRRB基因的转基因水稻对干旱的敏感性增强,表明NRRB正调控水稻对干旱的抗性;耐盐性分析表明,NRRB基因的抑制表达降低了植株对盐的敏感性。     

烟草幼苗响应弱光胁迫的转录组分析

为了研究烟草幼苗对弱光胁迫反应的分子机制,以'云烟87'为材料,构建全光照和弱光处理条件下大十字期烟苗cDNA文库,利用Illumina测序技术进行转录组测序,筛选差异表达基因.结果表明:借助RNA-seq技术共筛选到2 956个DEGs,其中弱光相对于全光照表达上调的DEGs有691个,表达下调的DEGs为2 265...     

Identification and Comparative Analysis of the Tegillarca granosa Haemocytes MicroRNA Transcriptome in Response to Cd Using a Deep Sequencing Approach

Background

MicroRNAs (miRNAs) are endogenous non-coding small RNAs (sRNAs) that can base pair with their target mRNAs, which represses their translation or induces their degradation in various biological processes. To identify miRNAs regulated by heavy metal stress, we constructed two sRNA libraries for the blood clam Tegillarca granosa: one for organisms exposed to toxic levels of cadmium (Cd) and one for a control group.

Results

Sequencing of the two libraries and subsequent analysis revealed 215 conserved and 39 new miRNAs. Most of the new miRNAs in T. granosa were up- or down-regulated in response to Cd exposure. There were significant differences in expression between the Cd and control groups for 16 miRNAs. Of these, five miRNAs were significantly up-regulated and 11 were significantly down-regulated in the Cd stress library. Potential targets were predicted for the 16 differential miRNAs in pre-miRNAs identified according to sequence homology. Some of the predicted miRNA targets are associated with regulation of the response to stress induced by heavy metals. Five differentially expressed miRNAs (Tgr-nmiR-8, Tgr-nmiR-21, Tgr-miR-2a, Tgr-miR-10a-5p, and Tgr-miR-184b) were validated by qRT-PCR.

Conclusion

Our study is the first large-scale identification of miRNAs in T. granosa haemocytes. Our findings suggest that some miRNAs and their target genes and pathways may play critical roles in the responses of this species to environmental heavy metal stresses.     

Response of Photosynthesis in Maize to Drought and Re-Watering

Russian Journal of Plant Physiology - The mechanism by which photosynthetic adaptation occurs in maize (Zea mays L.) during both drought and the subsequent recovery after re-watering is currently...     

脱落酸和己糖激酶抑制剂对高表达C4-PEPC转基因稻苗耐旱性的影响

为了研究高表达转玉米C₄-磷酸烯醇式丙酮酸羧化酶（phosphoenolpyruvate carboxylase,PEPC）基因水稻（PC）的耐旱性机制,本研究以PC和未转基因野生型原种kitaake为材料,分别在光照和黑暗预处理24 h,其中光照处理中光强为600 μmol·m^-2·s^-1,预处理后稻苗再在15％聚乙二醇-6000模拟干旱胁迫下,同时使用药理学的方法,通过加入脱落酸和己糖激酶的专一性抑制剂100 μmol·L^-1去甲二氢愈创木酸和10 mmol·L^-1葡萄糖胺,观察两种水稻4~5叶期稻苗耐旱表现。结果发现,与WT水稻相比,在PEG-6000处理后,经过光预处理的PC水稻叶片相对含水量下降较少,始终比WT的高,而且丙二醛含量则较少,脯氨酸诱导增加,表现耐旱;而经过暗预处理后PC植株显著降低这个优势,表明光预处理有利于PC耐旱性的表现;黑暗预处理均显著下调了2供试材料植株叶片中可溶性糖的含量,而对可溶性蛋白的含量影响不显著;而光预处理后PC水稻叶片内可溶性糖含量比WT增加,而在黑暗预处理则PC的显著低于WT的,其中葡萄糖胺对光预处理下PC的可溶性糖含量的下调作用最显著;暗预处理逆转或消除了NO,H₂O₂和钙离子含量变化趋势,这些变化与暗预处理减少了两材料叶片蔗糖和葡萄糖含量变化同步;光暗预处理对两材料的PEPC酶活性的差异影响不大,表明外源玉米C₄-PEPC在水稻中是组成型表达。可见PC叶片可部分通过糖组分,参与内源糖介导ABA和HXK信号途径,缓解干旱处理对叶片的伤害,稳定光合能力。     

拟南芥转录因子GRAS家族基因群响应渗透和干旱胁迫的初步探索

GRAS家族是一类植物特有的转录调控因子,已有报道表明该家族基因在植物生长发育和光信号转导过程中具有重要作用.目前在拟南芥(Arabidopsis thaliana)基因组中已鉴定了33个GRAS家族基因.利用功能基因组学和生物信息学手段,通过基因芯片数据挖掘和基因功能预测,对拟南芥GRAS家族基因在渗透和干旱胁迫过程中的应答模式进行了初步探索,提出了一类响应渗透胁迫和干旱胁迫的拟南芥GRAS家族基因.以SCL13为例,利用基因芯片相关性和GO分析,对其在渗透胁迫信号转导过程中可能的调控机制进行了预测和分析.这一研究将为阐明GRAS家族基因参与水分胁迫的分子机制提供新的思路,同时也为植物抗逆分子育种提供候选基因.     

Comparative Transcriptome Profile Analysis of Anther Development in Reproductive Stage of Rice in Cold Region Under Cold Stress

Plant Molecular Biology Reporter - Rice in cold region is threatened by cold stress frequently, resulting in severe losses of rice production. In the present study, two rice varieties with contrast...     

拟南芥转录因子GRAS 家族基因群响应渗透和干旱胁迫的初步探索

GRAS家族是一类植物特有的转录调控因子, 已有报道表明该家族基因在植物生长发育和光信号转导过程中具有重要作用。目前在拟南芥(Arabidopsis thaliana)基因组中已鉴定了33个GRAS家族基因。利用功能基因组学和生物信息学手段,通过基因芯片数据挖掘和基因功能预测, 对拟南芥GRAS家族基因在渗透和干旱胁迫过程中的应答模式进行了初步探索, 提出了一类响应渗透胁迫和干旱胁迫的拟南芥GRAS家族基因。以SCL13为例, 利用基因芯片相关性和GO分析, 对其在渗透胁迫信号转导过程中可能的调控机制进行了预测和分析。这一研究将为阐明GRAS家族基因参与水分胁迫的分子机制提供新的思路, 同时也为植物抗逆分子育种提供候选基因。     

Response of Split-Root Sour Orange Seedlings to NaCl and Polyethylene Glycol Stresses

Soil water cotent and salinity levels are seldom uniform inthe field, particularly with the use of micro-irrigation systemsthat may water only a portion of the root zone. For studyingnon-uniform salinity, a split-root experiment was designed toevaluate growth and water relations when half of the root systemof sour orange (Citrus aurantium) seedlings was stressed withsodium chloride (NaCl) or polyethylene glycol (PEG). This studyalso determined if non-stressed portions of the root systemcompensated for the decrease in water uptake by the stressedportions. One or both halves of the root system were treated for fourmonths with nutrient solution adjusted with NaCl or PEG to osmoticpotentials of –0.10, –0.20, or –0.35 MPa.Shoot dry weight was reduced by only 9% when half of the rootsystem was irrigated with saline solution at –0.10 MPa,but with both halves of the root system at –0.10 MPa,shoot and root dry weights were reduced as much as 45%. Similarly,leaf water and osmotic potentials were also more disturbed underuniform salinity than under non-uniform salinity conditions. Plant growth, leaf water potential, osmotic potential, stomatalconductance, and evapotranspiration decreased with increasingNaCl and PEG concentrations in the nutrient solution. Turgorpotential and leaf thickness increased in response to NaCl treatments.Microscopic examination showed that the increase in leaf thicknesswas due to the development of larger cells in the spongy mesophyll. Shoot growth did not correlate with the average osmotic potentialof the two root halves. Seedlings with one stressed half-rootsystem had shoot dry weight and leaf water potential valuescloser to those of the non-stressed control than to those withthe completely stressed root system. Key words: Non-uniform salinity, water relations, citrus