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…

Casparian strips, named after the German botanist Robert Caspary who discovered them, are a cellular feature found in the roots of all higher plants. They are ring-like lignin polymers deposited in the middle of anticlinal cell walls (parallel to the root radius) between endodermal cells. Along with…

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,…

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…

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…

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…

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…

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…