Project description:Precise regulation of cell proliferation and differentiation is a key factor for diversity in morphology during organogenesis. Rice palea comprises two distinct regions, the marginal region of palea (MRP) and the body of palea (BOP), which exhibit heterogeneity in cellular composition and behavior. This study reveals that REP1 promotes epidermal cell proliferation and differentiation in the BOP, forming hard silicified protrusion cells, by regulating the cyclin-dependent kinase gene, OsCDKB1;1. Conversely, OsMADS6 and OsMADS32 are expressed exclusively in the MRP, where they limit the division rates of epidermal cells by inhibiting OsCDKB2;1 gene expression, promoting endoreduplication and resulting in the formation of elongated epidermal cells. Furthermore, the OsMADS6-OsMADS32 complex and REP1 exhibit reciprocal inhibition to fine-tune the balance between cell division and differentiation during palea morphogenesis. Therefore, our study highlights the importance of controlling cellular heterogeneity in shaping plant morphological diversity.
Project description:The lemma, the palea and the awn of a barley spike are photosynthetic organs and supply the developing seed with carbohydrates. In addition, the lemma and the palea cover the seed and protect it from pathogens and insects. In this study, we compared gene expression among the lemma, the palea, the awn and the developing seed of barley at the grain-filling stage (Zadok scale 83) using the Barley1 Genome Array in order to identify genes that determine the primary function of these organs. Experiment Overall Design: Lemma, palea, awn and seed were collected at grain-filling stage (Zadok scale 83) to compare differences in gene expression. For each organ three biological replications were collected on three different dates. On each of the three dates, one replication of each organ was collected from plants grown in separate pots using a randomized complete block design (RCBD). In ths design, organ type was the treatment effect and date of sample collection (replication) was the block. To get enough tissue for RNA extraction, each replication for each organ was collected from four plants in the same pot. RNA from each replicate sample was hybridized to individual Barley1 GeneChips. Thus, for four organs with three replications (blocks), a total of 12 Barley1 GeneChips were used.
Project description:The photosynthetic organs of the barley spike (lemma, palea and awn) are resistant to drought. This is a beneficial trait because they can sustain grain-filling when drought occurs at the reproductive stage. There is little information about gene expression in the spike organs under drought conditions. In this study, we compared gene expression in drought-stressed lemma, palea, awn and seed at the grain-filling stage using the Barley1 Genome Array in order to identify drought-regulated organ-specific genes. Experiment Overall Design: Barley plants were drough-stressed for 4 days at the grain-filling stage by withholding water. Lemma, palea, awn and seed were collected to determine gene expression during drought in each organ. For each organ three biological replications were collected on three different dates. On each of the three dates, one replication of each organ was collected from plants grown in separate pots using a randomized complete block design (RCBD). In ths design, organ type and drought treatment were treatment effects and date of sample collection (replication) was the block. To get enough tissue for RNA extraction, each replication for each organ was collected from four plants in the same pot. RNA from each replicate sample was hybridized to individual Barley1 GeneChips. Thus, for four organs with three replications (blocks) and two treatment levels, a total of 24 Barley1 GeneChips were used.