Characterization of salt tolerance and Fusarium wilt resistance of a sweetpotato mutant

The variant LM1 was previously obtained using embryogenic cell suspension cultures of sweetpotato variety Lizixiang by gamma-ray induced mutation, and then its characteristics were stably inherited through six clonal generations, thus this mutant was named LM1. In this study, systematic characterization of salt tolerance and Fusarium wilt resistance were performed between Lizixiang and mutant LM1. LM1 exhibited significantly higher salt tolerance compared to Lizixiang. The content of proline and activities of superoxide dismutase（SOD） and photosynthesis were significantly increased, while malonaldehyde（MDA） and H_2O_2 contents were significantly decreased compared to that of Lizixiang under salt stress. The inoculation test with Fusarium wilt showed that its Fusarium wilt resistance was also improved. The lignin, total phenolic, jasmonic acid（JA） contents and SOD activity were significantly higher, while H_2O_2 content was significantly lower in LM1 than that in Lizixiang. The expression level of salt stress-responsive and disease resistance-related genes was significantly higher in LM1 than that in Lizixiang under salt and Fusarium wilt stresses, respectively. This result provides a novel and valuable material for improving the salt tolerance and Fusarium wilt resistance of sweetpotato.

The Potassium Transporter AtKUP12 Enhances Tolerance to Salt Stress through the Maintenance of the K^(+)/Na^(+)Ratio in Arabidopsis

Potassium(K^(+))is a necessary nutrient for plant growth and crop production.The K^(+)transporter plays crucial roles in the absorption and transport of K^(+)in plants.Most K^(+)transporters in Arabidopsis have been reported,but AtKUP12,which is a member of the KT/KUP/HAK family,has not yet been the subject of relevant in-depth research.In the present study,we demonstrated that AtKUP12 plays a crucial role in K^(+)uptake in Arabidopsis under 100μM low-K^(+)and 125 mM salt stress conditions.AtKUP12 transcripts were induced by K^(+)deficiency and salt stress.We analyzed the K^(+)uptake of AtKUP12 using the K^(+)uptake-deficient yeast R5421 and Arabidopsis mutant atkup12.Transformation with AtKUP12 rescued the growth defect of mutant yeast and atkup12 mutant plants at the low-K^(+)concentration,which suggested that AtKUP12 might be involved in high-affinity K^(+)uptake in low-K^(+)environments.In comparison to the wild-type(WT)and atkup12-AtKUP12 complementation lines,atkup12 showed a dramatic reduction in potassium concentration,K^(+)/Na^(+)ratio,and root and shoot growth on 12-day-old seedlings under the salt conditions;however,there was no significant difference between the complementation and WT lines.Taken together,these results demonstrate that AtKUP12 might participate in salt tolerance in Arabidopsis through K^(+)uptake and K^(+)/Na^(+)homeostasis.

Differential gene expression in salt-tolerant rice mutant and its parental variety

The differential expressions of three genes rbcL, salT and rab!6 in response to ABA, NaCl, PEG and heat shock were investigated in seedlings of a salt-tolerant rice mutant 20 (mutant 20) and its parental variety Oryza sativa var. japonica 77-170(170). By Northern blot analysis it was found that ABA induced the expression of all three genes of rbcL, salT and rab16 in shoots and roots of both 170 and mutant 20 with the exceptions of rab16 in shoots of mutant 20 and rbcL in roots of 170. Lower concentrations of NaCl induced rbcL expression in shoots of mutant 20 but not 170. Higher concentrations of NaCl decreased rbcL expression but induced expressions of salT and rab16 in shoots of both 170 and mutant 20. PEG(15%) and 37℃ heat shock showed almost no effects on the expression of the three genes in mutant 20. However, they caused a decrease in rbcL expression and slight induction of the rab16 gene in 170, with salT expression unaffected. These results indicated that mutant 20 was relatively less responsive to applied hormonal and environmental factors as compared with 170, suggesting that mutant 20 might have acquired mechanisms by which the plant is less responsive to environmental stresses and hence gain a stronger ability to tolerate stresses.

Analysis of genes specifically expressed under salt stress in salt-tolerant mutant of rice by using DDRT-PCR technique

Differential display reverse transcription-PCR (DDRT-PCR) technique was used to identify those genes that are expressed differentially between wild type rice variety 77-170 (Oryza Sativa vas Japonica) and its salt-tolerant mutant (M-20) under salt stress. Totally 13 salt-inducible cDNA fragments of 200-600 bp were identified and doned, and were designated as SIGR1 - SIGR13 (salt-induced gene in rice). Northern blot analysis showed that expression of SIGR6 and SIGR8 was salt-inducible in both wild type and mutant, and expression of SIGR12 in M-20 was much higher than that in 77-170 under salt stress. It was also shown that expression of SIGR3, SIGR4, SIGR7, SIGRIO and SIGR13 was salt-inducible, and the genes were highly homologous with Rab1d which was an ABA-inducible gene of rice. The great potential application of DDRT-PCR technique in plant molecular biology research may promote the investigation of expression of salt-induced protein in rice.

Enhanced H^+ transport activity of tonoplast vesicles isolated from roots of salt-tolerant mutant of wheat under NaCl stress

Both enhanced were H^+ transport activities of tonoplast vesicles isolated from roots of the salt-tolerant mutant and wild type of wheat with treatment of NaCI, but the activity of the mutant was significantly higher than that of wild type. H^+ transport activity was indicated as the stable value of fluorescence quenching per mg membrane proteins. The H^+ transport activities dependent on ATP of the mutant and wild type were 1099 and 558 respectively and their activities dependent on PPi were 358 and 228 separately.

利用RAPD-BSA技术筛选小麦耐盐突变位点的分子标记

以耐盐性差的“冀麦 2 4” (TriticumaestivumL .)和其经正定霉素诱变后获得的耐盐突变体 890 1_17为材料 ,用2 80个引物在两者之间进行RAPD分析 ,其中 35个引物扩增出DNA多态性 ,其相似性系数为 0 .978,证明二者为近等基因系 (near_isogenicline ,NIL)。用分株法建立两个F2 群体 (“冀麦 2 4”× 890 1_17和 890 1_17ד中麦 9”) ,在两个群体中按照BSA (bulkedsegregantanalysis)方法分别构建两个对应DNA池 (耐盐池和不耐盐池 ) ,用上述能扩增出明显多态性的 35个引物在对应的耐盐和不耐盐DNA池之间进行RAPD分析 ,发现只有OperonQ4引物在对应的两个DNA池扩增出的多态性在两个F2 群体之间是一致的 ,说明其扩增产物是与耐盐突变位点紧密连锁的RAPD分子标记。

Reduced Na^+ and K^+ permeability of K^+ channel in plasma membrane isolated from roots of salt-tolerant mutant of wheat

The Na^+ and K^+ permeability of K^+ channel in plasma membrane, isolated from roots of the salt-tolerant mutant of ,wheat, was lower than that of wild type in 100 mmol/L KCI and NaCI solution. The opening frequency of K^+ channel of the mutant reduced more significantly than that of wild type in two kinds of solution mentioned above. It is assumed that the reduction of opening frequency mainly contributes to the Na^+ and K^+ permeability of K^+ channel of the mutant. The electric conductance of single-channel of the mutant was similar to that of wild type and the main difference between them was exhibited as the opening frequency. Their K^+/Ka^+ selectivity of K^+ channel had no significant difference. The K^+/Na^+ selectivity of the mutant and wild type was 3.35 and 3. 18 respectively.

PCR-SSCP与测序技术相结合检测小麦耐盐突变体

根据位于小麦第四同源群上与耐盐有关的ｇｆ－２．８基因的编码区序列设计１对引物，分别以两个耐盐突变体及其亲本的总ＤＮＡ为模板进行ＰＣＲ扩增，在５个供试材料中均扩增出１条约６８５ｂｐ的目的条带。ＳＳＣＰ电泳显示突变体９７４９１５与其他供试材料之间存在差异。测序表明冀麦２４和其耐盐突变体８９０１－１７的扩增产物序列与ｇｆ－２．８基因的发表序列相同，这表明突变体８９０１－１７的突变位点不在该基因上；而另一耐盐突变体９７４９１５的序列中则至少存在２个单碱基突变，有一处突变导致了氨基酸的变化，该突变位点位于ｇｆ－２．８基因的保守区域内。

狼尾蕨体细胞耐盐突变体NY-7的耐盐性研究

通过盆栽实验,研究了不同盐浓度胁迫下狼尾蕨及其体细胞耐盐突变体NY-7的5个生理指标,并应用模糊隶属函数法对其耐盐性进行了综合评价。结果显示:随着NaCl浓度的升高和胁迫时间的延长,NY-7的叶绿素和可溶性蛋白含量下降,脯氨酸含量、SOD活性均没有显著变化,MDA含量有所增加;而狼尾蕨的叶绿素含量显著降低,SOD活性、脯氨酸、可溶性蛋白和MDA含量均显著增加;NY-7的耐盐性高于狼尾蕨。

^(60)Co-γ射线辐射甜叶菊诱变选育优质耐盐突变体

以甜叶菊叶片愈伤组织为突变体材料,创制并筛选耐盐突变体材料。采用^(60)Co-γ射线辐射对甜叶菊叶片愈伤组织进行诱变的方法,利用高盐培养基进行初步筛选,然后对初筛后的材料进行水培盐胁迫处理复筛(100 mmol·L^(-1)NaCl、60 mmol·L^(-1)Na_(2)SO_(4)、70 mmol·L^(-1)NaHCO_(3)营养液、处理20 d),研究突变体的株高、茎粗、节间长、叶鲜质量、茎鲜质量、叶干质量、茎干质量、叶长、叶宽等主要农艺性状,分析各类型糖苷含量,以期为甜叶菊优良品种选育提供参考依据。结果表明:经过辐射诱变后,成功得到13株再生苗,初步耐盐筛选共得到9份耐盐材料,复筛后得到7份耐盐突变体材料。1~3号为耐NaCl植株,4~7号为耐Na_(2)SO_(4)植株,未得到耐NaHCO_(3)突变体植株。7份耐盐突变体材料农艺性状和糖苷含量均出现了不同程度的变异,最终得到1份综合性状优良的耐NaCl突变体材料。通过对突变体的创制和筛选,共得到7份耐盐新材料,1份优良材料。

水稻组培耐盐突变体筛选体系的研究

本研究利用组培诱导突变体技术来开展水稻耐盐突变体筛选体系建立研究,为水稻育种新材料的获得提供新方法。本研究以‘日本晴’‘C418’‘C34’‘C210’四个粳稻品系为材料,利用N6+2.0 mg/L 2,4-D,附加4种不同NaCl浓度作为诱导培养基,进行水稻愈伤组织诱导和突变体筛选,同时结合再生植株生理指标测定。结果表明:随着NaCl浓度升高,水稻不同品系之间的愈伤诱导率及继代存活率总体趋势呈下降状态,在150 mmol/L达到最低;而愈伤组织分化率也呈现显著下降趋势,在150 mmol/L浓度下分化率为0%;通过再生植株叶片过氧化物酶(POD)活性测定发现该酶呈显著上升趋势,丙二醛(MDA)含量呈显著下降趋势,脯氨酸(Pro)含量呈显著上升趋势,因此综合以上结果分析认为,最佳的NaCl筛选浓度为100 mmol/L,对获得水稻耐盐突变体筛选最为有利,研究结果为水稻耐盐突变体诱导体系建立打下基础。

RAPD tagging of a salt tolerant gene in rice

A salt tolerant rice mutant was obtained through tissue culture. The inheritance of salt tolerance in F2 population of mutant crossed with its original variety under salt stress was studied. According to the standard, the ratio of salt tolerant: sensitive was about 3:1 suggesting that there was a major gene related to salt tolerance in the mutant. By RAPD analysis with 220 10mer primers, the gene was tagged by a 1.0 kb DNA fragment named OPS1210 which was located on chromosome 7. The genetic distance between the major salt tolerant gene was 16.4 cm.

小麦耐盐突变体的分子生物学鉴定

利用Ｆ１花药培养、ＥＭＳ诱变和耐盐性反复筛选后已稳定９ 代的小麦耐盐突变体ＲＨ８７０６－ ４９、Ｈ８７０６－ ３４、Ｈ８７０６－ ４４、Ｈ８７０６－ ４８、Ｈ８７０６－ ５７ 及其亲本濮农３６６５、百农３０３９ 为材料，用生化标记（醇溶蛋白）及分子标记（ＲＡＰＤ）分析了各材料间的差异，发现突变体与亲本相比，不仅发生了蛋白质水平的变异，而且也在ＤＮＡ 水平上证明了突变的发生，从而为耐盐突变体的真实性提供了有力的证据，排除了盐适应的可能性； 经用２１８ 个引物对５ 个突变体之间的多态性进行ＲＡＰＤ分析，结果表明，它们之间的差异很小，其遗传背景相似。

用微卫星标记定位小麦耐盐突变体的耐盐相关基因

以小麦耐盐突变体RH870 6 4 9×敏盐突变体H870 6 34(两者为“一粒传”后代 )的F2 群体作为基因定位群体 ,结合BSA法 (Bulkedsegregantanalysis ,群分法 ) ,对小麦耐盐突变体的耐盐相关基因进行了微卫星分子标记定位 ,在 2 4 6对微卫星引物中 ,微卫星标记Xgwm2 99与耐盐相关基因连锁 ,遗传距离为 5 .8cM ,定位于 3B染色体的长臂。

番茄耐盐体细胞变异体的离体筛选

以上海主要栽培番茄品种“鲜丰”的下胚轴作为外植体诱导愈伤组织 ,用 Na Cl进行直接高盐胁迫和逐渐加大盐浓度胁迫筛选。研究结果表明 ,逐渐加大 Na Cl浓度胁迫筛选获得的耐盐性大多属生理适应性 ,直接高盐胁迫筛选才有可能获得真正的耐盐突变体。直接高盐胁迫筛选再生出的 1 2株耐盐植株 ,在 1 5 0 mmol/L Na Cl的盐胁迫下 ,幼苗的成活率可达6 6 % ,而未经胁迫筛选过的原始株成活率则为零。其中 ,2株耐盐突变株能正常开花、结果。其后代在盐胁迫培养基中芽体的生根率。

短芒大麦耐盐碱新品系的生理生化和分子生物学分析

以经60 Co物理诱变种子、EMS诱变和耐盐反复筛选后已稳定 6代的短芒大麦耐盐碱突变体N1、T3 、T4、T5及其亲本野生短芒大麦为材料 ,进行耐盐碱生理生化指标 (脯氨酸、质膜透性 )测定及RAPD分析。发现突变体与野生型相比 ,不仅在生理生化指标上有明显的差异 ,而且在DNA水平上发生了突变。研究结果为耐盐碱突变体的真实性提供了有力的证据 ,表明突变体N1、T3 、T4、T5是耐盐碱短芒大麦新品系。

植物体细胞耐盐突变体的研究进展

植物体细胞耐盐突变体研究已经成为抗盐植物育种学研究的热点问题。综述了植物耐盐体细胞突变体筛选的试材确定、突变体筛选方法和突变体鉴定的研究现状,并指出植物耐盐突变体筛选还存在着变异类型复杂,变异方向难以控制,耐盐细胞系难以再生植株等缺陷。应加强高效稳定的植株再生体系建立;加强细胞悬浮培养技术研究,提高耐盐突变体筛选效率;提高耐盐目标性状的变异频率,减少非目的性状变异产生;从不同层面上加强耐盐突变体基础研究,提高突变体检测效果等方面研究,以提高植物体细胞耐盐突变体育种效果,更好地为实践和生产应用。

植物离体培养筛选耐盐突变体的研究

本文总结了利用离体培养系统筛选耐盐突变体的研究进展 ,分别从材料选择、变异来源、突变体的筛选等方面进行了讨论 ,概括了人工诱变离体培养材料的常用诱变剂及诱变剂量的选择 ;从生理生化及分子生物学等角度分析和归纳了耐盐突变体鉴定的研究进展 。

苹果砧木耐盐突变体的筛选鉴定及RAPD分析

对由诱变获得的苹果砧木78-48耐盐变异细胞系再生植株进行多代盐筛选,获得耐盐性稳定的突变体。并对突变体进行了RAPD分析,153个引物中有36个引物扩增出多态性,证明突变体在基因上发生了变化,为耐盐突变体的真实性提供了证据。

草莓离体诱变及耐盐筛选技术初探

以‘全明星’草莓组培苗为试材，分别用甲基磺酸乙酯（EMS）、^60Co-γ射线以及^60Co-γ射线＋EMS的复合诱变剂对叶片进行处理，并对‘全明星’草莓进行初步耐盐筛选。结果表明：EMS溶液处理草莓离体叶片适宜的浓度和时间是0．2％＋2．0h及0．4％＋1．0h，^60Co-γ射线诱变处理的剂量率为30R／min时，适宜的剂量为3～5kR，复合处理的适宜剂量为^60Co-γ（3kR）＋0．1％EMS处理2．0h及^60Co-γ（3kR）＋0．2％的EMS处理1．0h。对3种处理间进行比较发现，各处理的叶片存活率和再生率都比对照有所下降。其中，复合处理对草莓叶片的生理损伤作用显著提高，叶片的再生率比单一诱变剂处理下降了10％～15％。再生植株经过初步NaCl筛选后，复合诱变处理再生植株的生物产量显著高于其它处理，盐害率和盐害指数也都显著低于其它处理，表现出较强的耐盐性，而单一诱变剂处理之间的差异不显著。