Recent Posts

Synthetic hormone-responsive transcription factors can monitor an reprogram plant development

Development is driven by the activities of hormones which control expression of various traits. Modeling hormone pathways is complicated by extensive cross-talk, redundancy, and feedback loops. Khakhar et al. investigate the use of a technique known as Hormone Activated Cas9-based Repressors (HACRs)…

Reassessing the evolution of strigolactone synthesis and signaling

Much of our understanding of strigolactones (SLs) as developmental hormones and rhizosphere signals comes from studies of angiosperms. Understanding the ancestral role for strigolactones is complicated by the fact that some of the SL-related genes are closely related to those responsive to karrikins…

Non-Canonical Signaling of Ethylene Receptors

Ethylene is a gaseous plant hormone that affects the growth and development of plants and mediates plant stress responses. Ethylene is perceived by a family of five receptors in Arabidopsis thaliana including ETHYLENE RESPONSE1 (ETR1) and ETR2. Surprisingly, there are cases where the different ethylene…

Origin and Role of ABA in Stomatal Regulation

When the vapor pressure difference (VPD) between a leaf and the atmosphere increases (i.e., when air humidity decreases), guard cells lose turgor, thereby leading to stomatal closure. The evolution of this mechanism was an important step in the colonization of land by plants, since it enabled plants…

Extracellular ATP Boosts Plant Immunity Via Jasmonate Signaling

Damage-associated molecular patterns (DAMPs) are endogenous chemicals that are released from damaged cells and which play a role as “danger signals.” 
Adenosine 5’-triphosphate (ATP) becomes a DAMP signal after release into the extracellular milieu following cellular damage. Extracellular ATP…

New Insights into Wound-Induced Callus Formation

Plants repair wound sites through the formation of unorganized cell masses called calli, which can also serve as progenitors of new organs. Callus formation and organ regeneration often entail cell cycle re-entry of quiescent cells, which is achieved through the re-activation of core cell cycle regulators…

The tomato DELLA protein PROCERA acts in guard cells to promote stomatal closure

Nuclear accumulation of DELLA proteins induces transcriptional reprogramming and is well known to suppress the gibberellin (GA) pathway. While DELLAs can negatively regulate GA, increased GA levels can also signal DELLA degradation. GA is a growth-regulating hormone that is also involved in inhibiting…

Origin and Role of ABA in Stomatal Regulation

When the vapor pressure difference (VPD) between a leaf and the atmosphere increases (i.e., when air humidity decreases), guard cells lose turgor, thereby leading to stomatal closure. The evolution of this mechanism was an important step in the colonization of land by plants, since it enabled plants…

Members of the abscisic acid co-receptor PP2C protein family mediate salicylic acid-abscisic acid crosstalk

If we know anything about how ABA regulates plant response to environmental stresses it is that the pathway if very complicated and anything but straightforward. The ‘core’ ABA pathway is activated by first inhibiting a specific class of protein phosphatases, PP2Cs. This inhibition of PP2Cs allows…