Spatial and Temporal Expression of a Maize Lipid Transfer Protein Gene

Abstract

We studied the temporal and spatial pattern of lipid transfer protein (LTP) gene expression, as well as the localization of this protein, in maize. Using an LTP gene, we observed an accumulation of LTP mRNA in embryos and endosperms during seed maturation. LTP gene expression was also investigated in young seedlings. After germination, the leve1 of LTP mRNA in the coleoptile increased, with a maximum at 7 days, whereas LTP mRNA levels were low in the scutellum and negligible in roots. The high levels of LTP mRNA found in coleoptiles and embryos were confirmed by in situ hybridization. Moreover, LTP gene expression appeared to be localized in the externa1 cellular layers and around the leaf veins. Using immunogold methods, we also observed that LTP was distributed heterogeneously in the different cells of coleoptiles and leaves. The highest concentrations of LTP were found in the outer epidermis of the coleoptiles as well as in the leaf veins. Together, our observations indicate that LTP gene expression is not only organ specific and time specific but also cell specific.

Tissue-Specific Expression and Promoter Analysis of the Tobacco ltp1 Gene

“…This is in accord with our previous analysis of Ntltpl transcript distribution (Fleming et al, 1992) and with the various reports on lip gene expression performed in other species (Sossountzov et al, 1991;Clark and Bohnert, 1993;Fleming et al, 1993;Thoma et al, 1993Thoma et al, , 1994, in which at least some degree of epidermis specificity was described. However, even in mature leaves and stems at least some faint GUS staining was generally visible in nonepidermal tissue.…”

“…Such a specific localization of LTP in the epidermal cell wall is incompatible with a role in general lipid redistribution, and, in the light of a11 these observations, LTPs have been proposed to play a role in the transport of extracellular lipophilic material. This material could be required for the assembly of cutin (Sterk et al, 1991) and other amorphous barriers around the plant (Koltunow et al, 1990;Sossountzov et al, 1991;Kalla et al, 1994;Thoma et al, 1994).…”

The Differential Transcription Network between Embryo and Endosperm in the Early Developing Maize Seed

“…The outer cell layer gene family, which encode putative HD-ZP IV transcription factors (TFs), play a role in protoderm formation and maintenance (Ingram et al, 1999(Ingram et al, , 2000. The lipid transfer protein2 gene is specifically expressed in the abaxial protoderm of the scutellum and coleoptile (Sossountzov et al, 1991). knotted1 contributes to the formation of embryo shoot apical meristem (Smith et al, 1995;Kerstetter et al, 1997).…”

Patterns of expression of lipid-transfer protein gene in organs of Scots pine (Pinus sylvestris L.)

“…Зо-крема, нами було показано, що під дією СК і ЯК підвищується рівень експресії гена дефензину сосни (PsDef1) [3]. З літератури відомо, що ЯК індукує експресію LTP у арабідопсису, рису, перцю, пшениці, капусти, льону, а СК, у свою чергу, мала здат-ність індукувати експресію LTP у рису, арабідопсису, тютюну та льону [4,12,13,25,26,28]. Протилежний ефект дії цих гормонів на рівень експресії ліпідтрансферного протеїну ми спостерігали після обприскування ними проростків сосни.…”

“…Для кожного гена характерний складний профіль експресії, з чітко вираженою тканинною та органоспецифічністю, який залежить від стадії онтогенетичного розвитку рослинного організму і може змінюватися під впливом абіотичних та біотичних стресових чинників [4,12,13,26,30]. Експресія LTP виявлена в насінні, стручках, листках, стовбурах, пагонах, фруктах, квітках і коренях різних видів рослин.…”