Project description:Tropical and subtropical plants are generally sensitive to cold and can show appreciable variation in their response to cold stress when exposed to low positive temperatures. Using nylon filter arrays, we analyzed the expression profile of 1536 expressed sequence tags (ESTs) of sugarcane (Saccharum sp.) exposed to cold for 3-48 h. Thirty-four cold-induced ESTs were identified, of which 23 were novel cold-responsive genes that had not previously been reported as being cold-inducible. This series has the samples from replicate experiment number 1. Keywords = sugarcane, cold, nylon arrays Keywords: time-course
Project description:Tropical and subtropical plants are generally sensitive to cold and can show appreciable variation in their response to cold stress when exposed to low positive temperatures. Using nylon filter arrays, we analyzed the expression profile of 1536 expressed sequence tags (ESTs) of sugarcane (Saccharum sp.) exposed to cold for 3-48 h. Thirty-four cold-induced ESTs were identified, of which 23 were novel cold-responsive genes that had not previously been reported as being cold-inducible. This series has the samples from replicate experiment number 2. Keywords = sugarcane Keywords = cold Keywords = nylon arrays
Project description:Tropical and subtropical plants are generally sensitive to cold and can show appreciable variation in their response to cold stress when exposed to low positive temperatures. Using nylon filter arrays, we analyzed the expression profile of 1536 expressed sequence tags (ESTs) of sugarcane (Saccharum sp.) exposed to cold for 3-48 h. Thirty-four cold-induced ESTs were identified, of which 23 were novel cold-responsive genes that had not previously been reported as being cold-inducible. This series has the samples from replicate experiment number 1. Keywords = sugarcane, cold, nylon arrays
Project description:Tropical and subtropical plants are generally sensitive to cold and can show appreciable variation in their response to cold stress when exposed to low positive temperatures. Using nylon filter arrays, we analyzed the expression profile of 1536 expressed sequence tags (ESTs) of sugarcane (Saccharum sp.) exposed to cold for 3-48 h. Thirty-four cold-induced ESTs were identified, of which 23 were novel cold-responsive genes that had not previously been reported as being cold-inducible. This series has the samples from replicate experiment number 2. Keywords = sugarcane Keywords = cold Keywords = nylon arrays Keywords: time-course
Project description:In C4 sugarcane (Saccharum spp. hybrids), photosynthetic activity has been shown to be regulated by the demand for carbon from sink tissues. There is evidence, from other plant species, that sink-limitation of photosynthesis is facilitated by sugar-signaling mechanisms in the leaf that affect photosynthesis through regulation of gene expression. In this work, we manipulated leaf sugar levels by cold-girdling leaves (5oC) for 80 h to examine the mechanisms whereby leaf sugar accumulation affects photosynthetic activity and assess whether signaling mechanisms reported for other species operate in sugarcane. During this time, sucrose and hexose concentrations above the girdle increased by 77% and 81%, respectively. Conversely, leaf photosynthetic activity (A) and electron transport rates (ETR) decreased by 66% and 54%, respectively. Quantitative expression profiling by means of an Affymetrix GeneChip Sugarcane Genome Array was used to identify genes responsive to cold-girdling (56 h). A number of genes (74) involved in primary and secondary metabolic pathways were identified as being differentially expressed. Decreased expression of genes related to photosynthesis and increased expression of genes involved in assimilate partitioning, cell wall synthesis, phosphate metabolism and stress were observed. Furthermore four probe sets homologous to trehalose 6-phosphate phosphatase (TPP; EC 5.3.1.1) and trehalose 6-phosphate synthase (TPS; EC 2.4.1.15) were up- and down-regulated, respectively, indicating a possible role for trehalose 6-phosphate (T6P) as a putative sugar-sensor in sugarcane leaves.
Project description:In C4 sugarcane (Saccharum spp. hybrids), photosynthetic activity has been shown to be regulated by the demand for carbon from sink tissues. There is evidence, from other plant species, that sink-limitation of photosynthesis is facilitated by sugar-signaling mechanisms in the leaf that affect photosynthesis through regulation of gene expression. In this work, we manipulated leaf sugar levels by cold-girdling leaves (5oC) for 80 h to examine the mechanisms whereby leaf sugar accumulation affects photosynthetic activity and assess whether signaling mechanisms reported for other species operate in sugarcane. During this time, sucrose and hexose concentrations above the girdle increased by 77% and 81%, respectively. Conversely, leaf photosynthetic activity (A) and electron transport rates (ETR) decreased by 66% and 54%, respectively. Quantitative expression profiling by means of an Affymetrix GeneChip Sugarcane Genome Array was used to identify genes responsive to cold-girdling (56 h). A number of genes (74) involved in primary and secondary metabolic pathways were identified as being differentially expressed. Decreased expression of genes related to photosynthesis and increased expression of genes involved in assimilate partitioning, cell wall synthesis, phosphate metabolism and stress were observed. Furthermore four probe sets homologous to trehalose 6-phosphate phosphatase (TPP; EC 5.3.1.1) and trehalose 6-phosphate synthase (TPS; EC 2.4.1.15) were up- and down-regulated, respectively, indicating a possible role for trehalose 6-phosphate (T6P) as a putative sugar-sensor in sugarcane leaves. Twelve month-old field grown Saccharum spp. (L.) hybrid cv. N19 (N19) cultivated at Mount Edgecombe, KwaZulu-Natal (SASRI) were used in the study, which was conducted in November, 2006. Plants were grown on a 5 x 15 m plot located on a north-east facing slope with a gradient of ca. 10o. Cold-girdles were attached to sugarcane leaves (n=4) for a period of 56 h prior to harvest. The girdle consisted of 0.75 cm (diameter) soft plastic tubing, firmly clamped around each leaf, approximately 30 cm from the leaf base. Cooled water maintained at 5oC was then pumped through the tubing using a Grant LTD6G cooling bath (Grant Instruments, Barrington, Cambridge, UK). At harvest, leaf samples were immediately frozen in liquid nitrogen (–196oC) and subsequently milled in an A11 Basic Analysis Mill (IKA, Staufen, Germany). Ground leaf tissue was stored at –80oC in 50 ml centrifuge tubes prior to analysis.