Delaying reproduction until conditions are favorable is a key to success. FLOWERING LOCUS C is a well-known regulator of flowering that delays flowering until after winter vernalization. In the spring, FLOWERING LOCUS M (FLM) fine-tunes flowering time in response to ambient temperatures between 5ºC and 23ºC. Lutz et al. found that the expression level of […]
Many of the genes involved in the phosphate-stress response (PSR) have been identified from plants growing on sterile medium. Castrillo et al. examined how the root microbiota affectthe phosphate stress response, and how phosphate affects the association between roots and microbes. Plants deficient in the PSR failed to assemble wild-type microbiota, indicating that the PSR […]
Growth and cell proliferation at the shoot and root apexes are regulated by diverse factors including hormones, nutrients, and light. Previously, the protein kinase TOR (Target of Rapamycin), a transducer of glucose energy signals, was shown to phosphorylate and activate the transcription factor E2Fa, an activator of S-phase genes and cell division, in the root […]
Many seeds produce protease inhibitors that are thought to help protect them from pathogens and predation. One class are the Bowman-Birk Inhibitors (BBIs), which form folded loops that specifically bind to and inhibit trypsin and/or chymotrypsin proteases. Originally characterized from legumes, BBIs were subsequently identified in cereals, although those in cereals lack the chymotrypsin-inhibitory loop. […]
Previously, the rice PLA1 gene encoding a CYTOCHROME P450 (CYP78A) was shown to increase vegetative growth. Sun et al. enhanced expressed maize PLA1 specifically in the leaf growth zone under the control of the GA2ox promoter. Transgenic plants produced larger leaves and larger seed yields than control plants. Kinematic analysis revealed that the transgene increased […]
Capua and Eshed explored the link between auxin and leaf initiation at the shoot apical meristem, using the tomato mutant leafless (lfs), which is an ortholog of the Arabidopsis DORNRONSCHEN (DRN) and DRN-like (DRNL) genes that encode AP2-type transcription factors. The lfs mutant and the drn/drnl double mutant fail to form leaves, but instead form […]
MONOPTEROS is an auxin-response factor (ARF) that is necessary for root formation during early embryogenesis. Its activity is modulated by BODENLOS (BDL), an Aux/IAA protein that is degraded in the presence of auxin. Möller et al. investigated the transcriptional targets of MP in very early embryos through the cell-specific expression of a stabilized BDL protein […]
The transcriptional response to auxin depends in large part on the interactions between ARF transcription factors and the Aux/IAA transcription inhibitors that interact with them. The crucial role of auxin in embryo patterning is revealed by the embryo patterning defects observed in mutants of ARF and Aux/IAA proteins as well as auxin synthesis and transport […]
In leaf mesophyll cells, some of the sugars produced by photosynthesis are stored as transitory starch, which is then broken down to provide the cells with energy during the night. Recent advances in imaging and staining and the use of mutants have enabled the pattern of accumulation of transitory starch in guard cells to be […]