Figure 2 from the review by Takahashi et al. showing schematic diagram explaining CO2 sensing and signal transduction in stomatal guard cells. Top panel (A) shows a schematic model of the early receptor/sensor signal transduction mechanisms under low/high levels of CO2 and ABA conditions. Bottom panel (B) shows the dominant mutations of HT1 (A109V and R102K) that impair CO2 sensing by disrupting MPK4/12 binding, which can activate CBC1 and cause CO2-insensitive constitutive open stomata in dominant mutant plants. These HT1 mutations may have a similar effect to the well-known ABA-insensitive PP2C mutations, abi1-1 and abi2-1, which disrupt ABA-dependent binding to PYL/RCARs thereby impeding inhibition of their phosphatase activity, resulting in open stomata and strong ABA-insensitivity.
Sense and Sensibility...
Takahashi, @natiwongpan.bsky.social et al. discuss recent genetic studies identifying key signalling molecules that underpin CO2 sensing by #stomata; such findings could help improve water use efficiency in plants
Open Access: doi.org/10.1093/pcp/...
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