| Evidence category | Key findings | Source (first author year) | Publication date | URL | Citation ID(s) |
|---|---|---|---|---|---|
| identity/domains | CASPL1D2 is the Arabidopsis thaliana gene At3g06390 and belongs to the CASP/CASPL family; CASP/CASPL proteins are DUF588/PF04535-containing, typically four-transmembrane proteins within a MARVEL-related family associated with Casparian strip membrane domains. | Champeyroux 2019; Xue 2024; Barbosa 2023 | Mar 2019; Sep 2024; Jul 2023 | https://doi.org/10.1111/pce.13537; https://doi.org/10.3390/ijms25189858; https://doi.org/10.1038/s41467-023-37265-7 | (pqac-00000028, pqac-00000017, pqac-00000012) |
| expression pattern | Reporter analyses showed CASPL1D2 expression in root endodermis and cells overlying lateral root bases, absent from young tissues, and specifically associated with suberized endodermal cells; 2024 comparative analyses also place many AtCASP/CASPL genes in root/endodermal expression programs. | Champeyroux 2019; Xue 2024 | Mar 2019; Sep 2024 | https://doi.org/10.1111/pce.13537; https://doi.org/10.3390/ijms25189858 | (pqac-00000000, pqac-00000004, pqac-00000018, pqac-00000019) |
| subcellular localization | GFP fusion data localized CASPL1D2 to the plasma membrane of endodermal cells and showed it is excluded from the Casparian strip membrane domain (CSD), distinguishing it from core CASP scaffold proteins. | Champeyroux 2019 | Mar 2019 | https://doi.org/10.1111/pce.13537 | (pqac-00000000) |
| molecular interactions | CASPL1D2 was identified among PIP2;1-associated proteins and showed physical interaction with the aquaporin PIP2;1 by FRET-FLIM, but unlike CASPL1B1 it did not measurably stimulate PIP2;1 water transport in Xenopus oocytes. | Champeyroux 2019 | Mar 2019 | https://doi.org/10.1111/pce.13537 | (pqac-00000002, pqac-00000005) |
| mutant/phenotype | caspl1d1 caspl1d2 double mutants showed only weak/inconsistent enlargement of the continuous suberization zone and no major defects in total solute uptake, suberin barrier permeability, root hydraulic conductivity, or growth under tested control/NaCl/ABA conditions. In a 2023 CASP redundancy test, adding caspl1d2 and five other CASPL knockouts to caspQ did not worsen the caspQ phenotype. | Champeyroux 2019; Barbosa 2023 | Mar 2019; Jul 2023 | https://doi.org/10.1111/pce.13537; https://doi.org/10.1038/s41467-023-37265-7 | (pqac-00000003, pqac-00000004, pqac-00000024, pqac-00000026) |
| pathway/regulation | CASPL1D2 appears linked to endodermal suberization/stress-responsive programs rather than the core CASP scaffold for Casparian strip initiation. It is strongly induced in MYB41 overexpressors, and CASPL1-clade genes including CASPL1D2 were noted among endodermis/CIF2-responsive candidates, but CASPL1D2 did not compensate for CASP loss during early Casparian strip formation. | Champeyroux 2019; Barbosa 2023; Xue 2024 | Mar 2019; Jul 2023; Sep 2024 | https://doi.org/10.1111/pce.13537; https://doi.org/10.1038/s41467-023-37265-7; https://doi.org/10.3390/ijms25189858 | (pqac-00000003, pqac-00000007, pqac-00000024, pqac-00000019) |
| key quantitative data | CASPL1D2 expression was reduced by >89% in mutant lines; it was reported as the most highly upregulated gene in MYB41 overexpressors (~300-fold). In suberization assays, continuous suberization was 42% in caspl1d1 caspl1d2 versus 36% in control under one condition; after 6 h ABA both reached 58%, and after NaCl ~50% (control) versus 56% (double mutant). FRET-FLIM with PIP2;1 reduced CASPL1D2-GFP lifetime from 2247 ± 12 ps to 2171 ± 6 ps (FRET efficiency 1.9%, P = 4.40 × 10−4). ABA reduced Lpr-h similarly in WT and double mutant (53% vs 49%), while 100 mM NaCl caused a stronger trend in the double mutant (70% vs 52%). Reporter patterning was described as discontinuous over ~29% of mid-root length then continuous over ~29% of basal root length. | Champeyroux 2019 | Mar 2019 | https://doi.org/10.1111/pce.13537 | (pqac-00000000, pqac-00000002, pqac-00000003, pqac-00000005, pqac-00000029) |


*Table: This table summarizes gene-specific and family-level functional annotation evidence for Arabidopsis CASPL1D2/At3g06390, including localization, interactions, phenotypes, regulation, and quantitative findings. It is useful as a compact evidence map showing where direct data exist and where inference depends on broader CASP/CASPL biology.*