植物學(xué)

植物學(xué)

封面介紹：Cysteine as well as sulfate inhibits primary root elongation in a dosage dependent manner. In this issue，Wang et al.（pp. 186-197）demonstrate that cysteine regulates the expressions of PLT1/2，SCRand SHR genes to maintain the stem cell niche in root meristem.

L-Cysteine inhibits root elongation through auxin/PLETHORA and SCR/SHR pathway in Arabidopsis thaliana

Zhen Wang，Jie-Li Mao，Ying-Jun Zhao，et al.

L-Cysteine plays a prominent role in sulfur metabolism of plants. However，its role in root development is largely unknown. Here，we report that L-cysteine reduces primary root growth in a dosage-dependent manner. Elevating cellular L-cysteine level by exposingArabidopsis thaliana seedlings to high L-cysteine，buthionine sulphoximine，or O-acetylserine leads to altered auxin maximum in root tips，the expression of quiescent center cell marker as well as the decrease of the auxin carriers PIN1，PIN2，PIN3，and PIN7 of primary roots. We also show that high L-cysteine significantly reduces the protein level of two sets of stem cell specific transcription factors PLETHORA1/2 and SCR/SHR. However，L-cysteine does not downregulate the transcript level of PINs，PLTs，or SCR/SHR，suggesting that an uncharacterized post-transcriptional mechanism may regulate the accumulation of PIN，PLT，and SCR/SHR proteins and auxin transport in the root tips. These results suggest that endogenous L-cysteine level acts to maintain root stem cell niche by regulating basal- and auxin-induced expression of PLT1/2 and SCR/SHR. L-Cysteine may serve as a link between sulfate assimilation and auxin in regulating root growth.

Auxin； L-cysteine； PIN； PLETHORA； root stem cell； root system architecture

來源出版物：Journal of Integrative Plant Biology，2014，57（2）： 186-197聯(lián)系郵箱：Cheng-Bin Xiang，xiangcb@ustc.edu.cn

氣體甲醛脅迫對蠶豆保衛(wèi)細胞中過氧化氫的積累和氣孔導(dǎo)度及開度的影響

孫慧群，周升恩，吳懷勝，等

摘要：以蠶豆為材料，考察氣體甲醛（HCHO）脅迫對保衛(wèi)細胞H2O2積累和葉片氣孔導(dǎo)度、開度的影響.結(jié)果表明：氣體HCHO脅迫增加了葉片中H2O2的積累，熒光顯微分析發(fā)現(xiàn)在較低濃度（0.2～0.4 μmol?L-1）氣體HCHO脅迫下，保衛(wèi)細胞中增加的H2O2主要分布在細胞質(zhì)中，高濃度（0.8～1.6 μmol?L-1）氣體HCHO脅迫不僅增加保衛(wèi)細胞質(zhì)中H2O2的積累，而且顯著增加葉綠體中H2O2的含量及積累H2O2的葉綠體數(shù)量，這說明在高濃度氣體HCHO脅迫下蠶豆保衛(wèi)細胞中增加的H2O2主要來源于葉綠體和細胞質(zhì).保衛(wèi)細胞中H2O2積累的增加顯著降低蠶豆的氣孔導(dǎo)度和開度，從而導(dǎo)致蠶豆HCHO吸收效率下降.氣體HCHO脅迫下葉片中抗氧化酶活性的變化可能是H2O2積累增加的主要原因，氣體HCHO脅迫顯著增強葉片中CAT和SOD的活性，但只有低濃度HCHO脅迫誘導(dǎo)葉片POD活性，葉片APX對HCHO脅迫很敏感，低濃度的氣體HCHO對葉片APX活性都有顯著的抑制作用.

關(guān)鍵詞：氣體甲醛脅迫；蠶豆；保衛(wèi)細胞；過氧化氫積累；抗氧化酶

來源出版物：植物生理學(xué)報，2015，51（2）： 246-252 聯(lián)系郵箱：陳麗梅，chenlimeikm@126.com

北方澙湖大葉藻植株枚訂移植法的效果評估與適宜性分析

劉燕山，郭棟，張沛東，等

摘要：2009年利用植株枚訂移植法在我國北方典型澙湖——山東榮成天鵝湖逐月進行大葉藻（Zostera marina）植株移植，并于當年逐月對移植植株的存活率、定居時間和生長進行監(jiān)測，分析該方法在我國北方澙湖的有效性和適宜性.結(jié)果顯示：（1）4-6月移植植株的存活率為76.5%-90.4%，其中4月移植植株的存活率最低，7-9月移植植株的存活率達到100%；（2）6-9月移植植株的定居時間均為1個月，5月移植植株的定居時間為2個月，而4月移植植株的定居時間長達4個月；（3）除個別監(jiān)測月份外，移植植株的葉長和葉鞘長均顯著小于天然植株，而莖節(jié)直徑和根長均與天然植株無明顯差異；（4）我國北方澙湖較適宜大葉藻植株移植的區(qū)域為海水透明度高、水深不超過1 m的潮下帶，且底質(zhì)為泥含量較高的泥砂底質(zhì)海區(qū)，9月份是適宜的移植時間.

關(guān)鍵詞：大葉藻；枚訂法；存活率；定居時間；生長；海草

來源出版物：植物生態(tài)學(xué)報，2015，39（2）： 176-183

聯(lián)系郵箱：張沛東，zhangpdsg@ouc.edu.cn