Genetic Mechanism of Root Meristematic Activity

;​R o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o,'() * +, -。/ 0 F Microsoft Word 6.0 Document MSWordDoc6;MZ} @ @签到日期s}+“签到时间# s}，‘签到说明# s}% ’支付小时表列表+ s}‘签到日期的参观时间* s}（’签到日期的参观类型‘ s}） ’ T 9513522 Sung的小时类型指标拟议的研究将使用一组拟南芥根系突变体来表征根系连续生长所需的基因。这些突变体被称为根无分生组织（rml），其在根端启动和维持细胞分裂的能力受损，导致根长1-2毫米的无分生组织。互补分析鉴定了两个RML基因，RML1和RML2，分别定位在第4染色体和第3染色体上。虽然rm1突变体产生正常的胚胎根，但根的顶端细胞在萌发后不进行细胞分裂，或细胞分裂有限。rm1突变体能够产生侧根和不定根，然而，一旦达到胚胎根的大小，这些根也会阻止细胞分裂。我们推测这两个野生型RML基因参与了介导根尖细胞增殖的信号转导通路。为了验证这一假设，宋博士将鉴定和克隆参与根尖细胞增殖的基因。首先克隆RML1基因，建立分子探针，研究RML1基因在野生型和突变型植物中的时空表达。将对35S:RML1转基因植株的表型进行表征，以寻找支持RML1基因作用的证据。长期目标是了解植物中局部细胞增殖的原理和机制。*** ;Oh + 0 $ H + 1 $ H + 1 $ H + 1 $ H + 1 $ H + 1 $ H + 1 $ H + 1 $ H + 1 $ H + 1 $ H + 1 $ H + 1 $ H + 1 $ H + 1 $ H + 1 $ H + 1 $R:模板\ WWUSER \ \正常。DOT 9513522 eozsaruh eozsaruh @ M @ @ M @ f# Microsoft Word 6.0 2;;e = e j j j j j j j j H 1 * y T + H j j j j j拟南芥的研究将利用一组拟南芥根系突变体来表征根系连续生长所需的基因。这些突变体被称为根无分生组织（rml），其在根端启动和维持细胞分裂的能力受损，导致根长1-2毫米的无分生组织。互补分析鉴定了两个RML基因，RML1和RML2，分别定位在第4染色体和第3染色体上。虽然rm1突变体产生正常的胚胎根，但根的顶端细胞在萌发后不进行细胞分裂，或细胞分裂有限。rm1突变体能够产生侧根和不定根。然而，一旦达到胚胎根的大小，这些根也会阻止细胞分裂。我们推测这两个野生型RML基因参与了介导根尖细胞增殖的信号转导通路。为了验证这一假设，宋博士将鉴定和克隆参与根尖细胞增殖的基因。首先将克隆RML1基因，以开发用于研究的分子探针

; R o o t E n t r y F @ C o m p O b j b W o r d D o c u m e n t O b j e c t P o o l & ' ( ) * + , - . / 0 F Microsoft Word 6.0 Document MSWordDoc Word.Document.6 ; MZ} e@ @ Sign-out Date s}+ ' Sign-out Time # s}, ' Sign-out Explanation # s}% ' Pay Hours Table List + s}' ' Tour Hours for Sign-out Date * s}( ' Tour Type for Sign-out Date 0 s}) ' " Hour Type Indicator for T 9513522 Sung The proposed research will use a set of Arabidopsis root mutants to characterize the genes necessary for continuous root growth. These mutants, called root meristemless (rml), are impaired in the ability to initiate and maintain cell division in the root apex, resulting in meristemless roots of 1-2 mm in length. Complementation analysis has identified two RML genes, RML1 and RML2, which are mapped to chromosome four and three, respectively. Although rml1 mutants produce normal embryonic roots, root apical cells undergo no, or limited, cell division after germination. rml1 mutants are able to initiate lateral and adventitious roots, However, these roots also arrest cell division once the size of the embryonic root is reached. It is hypothesized that the two wild type RML genes are involved in the signal transduction pathway mediating cell proliferation at the root tip. To test this hypothesis, Dr. Sung will identify and clone the genes involved in root apical cell proliferation. The RML1 gene will be cloned first to develop a molecular probe for studying the temporal and spatial expr ession of the RML1 gene in the wild type and mutant plants. The phenotype of the 35S:RML1 transgenic plants will be characterized to seek evidence supporting the proposed role of the RML1 gene. The long term goal is to understand the principles and mechanisms of localized cell proliferation in plants. *** ; Oh +' 0 $ H l D h S u m m a r y I n f o r m a t i o n ( % R:\WWUSER\TEMPLATE\NORMAL.DOT 9513522 eozsaruh eozsaruh @ M @ @ M @ F # Microsoft Word 6.0 2 ; ; e = e j j j j j j j H 1 * y T + H j H j j j j ~ j j j j B 9513522 Sung The proposed research will use a set of Arabidopsis root mutants to characterize the genes necessary for continuous root growth. These mutants, called root meristemless (rml), are impaired in the ability to initiate and maintain cell division in the root apex, resulting in meristemless roots of 1-2 mm in length. Complementation analysis has identified two RML genes, RML1 and RML2, which are mapped to chromosome four and three, respectively. Although rml1 mutants produce normal embryonic roots, root apical cells undergo no, or limited, cell division after germination. rml1 mutants are able to initiate lateral and adventitious roots. However, these roots also arrest cell division once the size of the embryonic root is reached. It is hypothesized that the two wild type RML genes are involved in the signal transduction pathway mediating cell proliferation at the root tip. To test this hypothesis, Dr. Sung will identify and clone the genes involved in root apical cell proliferation. The RML1 gene will be cloned first to develop a molecular probe for studyin