Q2. What tools could be used to study the role of cytokinins in plant development?
the use of molecular tools including CKI, SRDX and EAR motifs in combination with tissue specific promoters could be useful to study the role cytokinin signaling in specific developmental processes.
Q3. What is the role of cytokinins in vascular development?
Root meristem size determination Besides a role in controlling radial patterning and proliferation, cytokinins also regulate root development in a longitudinal sense.
Q4. What is the role of ETTIN/ARF3 in flower determinacy?
The prolonged WUS expression within the arf3-29 mutant further suggests that ETTIN/ARF3 repression of cytokinin signaling is necessary for flower determinacy, potentially by limiting WUS expression.
Q5. What is the role of cytokinins in the development of female gametophytes?
Based on these results and the specific expression in the different cell types of the female gametophyte [37], it is clear that CKI is important to provide antipodal and central cell fate, whereas repression of CKI is required for synergid and egg cell specification.
Q6. How does the cytokinin signaling in the medial tissues work?
This is achieved by inducing the cytokinin inhibitor AHP6 within these tissues [30, 31, 33], whereas AG represses cytokinin signaling by directly inducing A-type ARRs [34].
Q7. What could be the main reason for the diversity of cytokinin responses?
The presence of other transcriptional regulators that co-regulate the cytokinin response could also partly explain how diverse cytokinin responses can be activated.
Q8. What is the relationship between auxins and cytokinins?
This bilateral character of the vasculature is a consequence of a tight interplay between auxins and cytokinins, as the auxin signaling in xylem cells induces AHP6 which in turn represses cytokinin signaling [44].
Q9. What is the main limitation of the DR5 and TCS type of reporters?
The main limitation of the DR5 and TCS type of reporters is that they do not visualize actual cytokinin levels, but the responses.
Q10. What is the role of cytokinins in the development of shoot cells?
Cytokinin controls shoot cell fateCytokinin signaling was shown to be vital in the context of shoot apical meristem (SAM; see Glossary) development (Key Figure 1), being able to induce shoot formation in callus [6, 8].
Q11. What is the role of cytokinin signaling in the cki mutant?
The role of cytokininsignaling is emphasized as the TCS expression (Box 1) in these cells is reduced or absent in the CKI/cki and cki1-9 mutant backgrounds respectively [37].
Q12. What is the significance of the interplay between auxins and other phytohormones?
as postulated decades ago, the specific interplay between cytokinins and other phytohormones emerges as an essential property for normal plant development.