[Objective] This study researched the sources of H2 O2 in maize subsidiary cells to clarify the co-regulation mechanism of guard cells and subsidiary cells in grassy stomatal movement.[Method] This study researched the cell localization of H2O2 by cytochemical fluorescent probe and analyzed the gene expression of ZmPIP2;4,ZmPIP2;5,ZmPIP2;6 by qPCR technology,with Tubulin and GAPDH as reference genes.Then the fact of aquaporin facilitates transmembrane diffusion of H2 O2 in maize subsidiary cells was confirmed.[Result] Under light and dark treatments,the accumulation of H2 O2 in subsidiary cells was opposite to the control group supplemented with aquaporin inhibitor AgNO3.Exogenous H2O2 caused H2 O2 accumulation in subsidiary cells,but aquaporin inhibitor AgNO3 added before the addition of exogenous H2 O2 did not cause H2 O2 accumulation.After short cells appeared,H2 O2 started to accumulate in subsidiary cells,at the same time the gene expression of ZmPIP2;5 was upregulated.After short cells appeared,the expressions of ZmPIP2;4,ZmPIP2;5 and ZmPIP2;6 were upregulated when increased soil water shortages.[Conclusion] Aquaporin can transport H2 O2 in leaf epidermis of maize and H2O2 in subsidiary cells was exogenous,whose accumulation and elimination were possibly mediated by aquaporin ZmPIP2;5.

通过盆栽控水方式,以冬小麦小偃22叶片为实验对象,利用生理指标测定、光合测定和H2DCFDA荧光标记等相结合的方法,研究了4个水分处理下(正常供水CK;轻度亏水LS;中度亏水MS;重度亏水SS),冬小麦叶片中活性氧含量、丙二醛(MDA)含量、活性氧清除系统的相关保护酶活性及水分胁迫情况下过氧化氢(H2O2)在小麦叶片内的分布情况,同时,还探讨了不同水分胁迫处理对小麦气孔的密度及光合性能指标的影响,结果表明,随着水分胁迫程度的加剧,小麦叶片内H2O2和MDA含量逐渐增加;叶片的气孔密度增加,其中重度胁迫较正常灌溉情况气孔密度增加了44.12％;而光合性能指标(蒸腾速率、光合速率、气孔导度和叶肉细胞间CO2浓度)随水分胁迫的加剧呈下降的趋势.H2O2在叶表皮中的含量随水分胁迫加剧呈增加趋势,且在重度胁迫情况下分布较其他情况更广.本实验为小麦抗旱机理的研究提供了实验依据,为解决旱区农业作物种植问题提供了一定的理论指导.

采用大田试验,直接撕表皮或对叶片进行固定处理,结合单染、复染、荧光染色等多种细胞学显色方法,利用光学显微镜、荧光显微镜和扫描电子显微镜系统观察玉米叶表皮短细胞的发生时期、发育过程、分布规律以及形态结构特征,研究K+和H2O2在栓质细胞中的分布变化与表皮其它细胞中K+和H2O2的分布及气孔器开关的关系,为进一步挖掘短细胞的新功能提供细胞学依据.结果表明:(1)短细胞是同步发生在玉米多叶位新表皮组织形成过程中,所有植株从第7新生叶,大部分第6叶,极少数第5叶的基部同时开始发生短细胞,之后新生的高位叶也均发生短细胞,并随着叶位的升高叶片各部位短细胞密度均增大,所有植株的l～4叶(因不再生长)均无短细胞出现.(2)初期发育的叶表皮细胞进行不对称分裂,生成相互交替的长、短细胞,有的短表皮细胞横(垂直叶脉)分裂,形成栓质细胞和硅质细胞对;栓质细胞基部与叶肉细胞相邻,硅质细胞嵌在栓质细胞和表皮细胞间偏上.(3)有短细胞发生的叶片,宏观背面发亮且覆有蜡质层,微观表皮细胞的着色特性发生了变化;栓质细胞为面包形柱状细胞,硅质细胞为哑铃形扁细胞.(4)气孔器张开时,栓质细胞中没有K+和H2O2的积累;气孔器关闭时,栓质细胞中积累了大量的K+和H2O2,且栓质细胞中K+和H2O2的积累始终与副卫细胞中K+和H2O2的积累变化一致,而硅质细胞和长细胞没有K+和H2 O2的积累.该研究确定了玉米叶表皮短细胞发生的时期;展示了其发育过程的形态学变化特征;发现栓质细胞中K+和H2O2的积累随气孔器开关呈周期性变化,且与副卫细胞中K+和H2O2的积累变化保持一致.

Anin situ detection method for K+ was found with maize leaves as the materials in this paper. The distribution of sodium lead cobaltinitrite [NaPbCo(NO2)6] in submicroscopic structures of plant cells was ob-served by means of the production of KPbCo(NO2)6, which precipitated to form electronic impermeable parti-clesin situ, when NaPbCo(NO2)6 reacted with K+. We found K+ is mainly distributed in the vascular bundles, cell membrane, chloroplasts, nuclei and nucleoli using this method, which is considerably consistent with cur-rent research results. The method has advantages of high sensitivity and specificity in coloration, with cell structure of plant tissue remaining relatively intact. Therefore, this method can be used as a new technology in detecting K+ in plant submicroscopic structuresin situ.

Seedlings of the popular maize cultivar "Zhengdan-958" growing in pots individually were exposed to suitable soil water conditions as control, light water shortage, moderate water shortage, and severe water shortage, corresponding to soil water contents between 75%-85%, 65%-75%, 55%-65%, and 45%-55% of field water capacity, respectively. Responses of stomatal aperture, Kranz anatomy, and vascular bundle structure to different water contents of maize leaves were investigated. Results showed that under increased water shortages, the levels of H2O2 in both guard cells and subsidiary cells were enhanced, also the fluorescence intensity of H2O2 labeled with fluorescent dye increased, while stomatal aperture and conductance decreased gradually. Moreover, Kranz cells were messily arranged and the cell size became smaller and smaller, and the structure of bundle sheath cells went irregular; and the sectional area of the big bundle and xylem, the cell number of phloem, and the thickness of whole leaf and of upper and lower epidermis reduced. In addition, the number of chloroplasts in mesophyll cells and vascular bundle sheath cells decreased, particularly under the moderate water deficit, chloroplasts in Kranz cells which located in the inside of cytoplasmic membrane and cling on the cell wall spread to the direction of cell center. It demonstrated that stomatal closing of maize could be regulated by H2O2 in guard cells and subsidiary cells together, and H2O2 in subsidiary cells maybe played a cooperative role. In conclusion, under increased soil water shortages, drought-induced H2O2 accumulations in both guard cells and subsidiary cells of maize leaves participated in the regulation of stomatal closing. And, the size of Kranz cells and bundle sheath cells, the cell number of phloem, and the area of the xylem and phloem re- duced, thereby, reducing water shortage-induced damage.

In order to quickly and efficiently generate optimized data model and fluently and vividly carry out 3D scene rendering of hydraulic engineering,the paper used OSG(Open Scene Graph) program to develop a 3D simulation of dam and roaming demo system in 3Dmodeling and visualizatrion of dam,the 3D rendering of this system will make the scene more intuitive and true.Research shows that the OSG program has support on high performance rendering,massive terrain database and multi channel,the application prospect of OSG platform in the 3D simulation system design of dam area is very wide,the importance of simulation of 3D visualization research is increasingly prominent.

Based on two periods of China-Brazil earth resource satellite,we obtained the upper reaches of the Yellow River Basin in 2004 and 2009 of Ningxia land use data.Through the massive studies and the synthesis comparison of many kinds of methods,we had obtained the interpretation key of various land types.Finally,we analyzed the application of error matrix method to measure the accuracy of classification in this paper.The analysis indicated that this area has already had definite progress but at lower speeds.Recently soil and water conservation measures,such as aforestation,have showed some positive efforts which related to the implementation of the policy of wetland protection with the local government.