The Tomato DELLA Protein PROCERA Promotes Abscisic Acid Responses in Guard Cells by Upregulating an Abscisic Acid Transporter

Abstract

The tomato DELLA protein PROCERA promoted abscisic acid-induced stomatal closure and gene expression by upregulating the expression of the ABA transporter ABA-IMPORTING TRANSPORTER 1 in guard cells. List of author contributions: H.S. performed most of the experiments. Y.K. performed transport assays in yeast. N.I-E. provided some of the materials used in this study, H.S, M.S. and D.W. designed the experiment and analyzed the experimental data. H.S., M.S. and D.W. wrote the manuscript.

Inhibition of gibberellin accumulation by water deficiency promotes fast and long‐term ‘drought avoidance’ responses in tomato

“…1b). Comparing transcript levels of all GA2oxs in isolated WT guard cells using available RNA‐seq data (Shohat et al ., 2020), revealed that GA2ox7 expression was much higher than all other GA2oxs (Fig. S2).…”

“…A rapid and efficient guard‐cell isolation procedure (see methods in Shohat et al ., 2020) was used to examine if water deficiency affects GA accumulation in guard cells. This rapid procedure was taken to minimise the effect of the isolation process on transcription and hormone metabolism.…”

“…3 and 4 below the apex) were isolated according to Shohat et al . (2020). Briefly, four fully expanded leaves without the central veins were ground twice in a blender containing 100 ml cold distilled water, for 30 s each time.…”

“…The effects of pro∆17 on stomatal closure and water loss were suppressed in the ABA‐deficient sitiens ( sit ) mutant, indicating that these effects of DELLA are ABA dependent (Nir et al ., 2017). High levels of DELLA promoted the expression of the ABA transporter gene ABA‐IMPORTING TRANSPORTER1.1 ( AIT1.1 ) in guard cells, and the ait1.1 mutant suppressed the effect of DELLA on ABA‐induced stomatal closure and transpiration (Shohat et al ., 2020). These changes suggest that AIT1.1 mediates, at least partially, the effect of DELLA on stomatal closure.…”

ABA homeostasis and long-distance translocation are redundantly regulated by ABCG ABA importers

“…Several ABA transporters have been identified so far. In Arabidopsis , ABCG40 imports ABA into guard cells ( 15 , 45 ), and in tomato, AIT1.1 was recently shown to play a role in ABA import into guard cells in an aspartic acid–glutamic acid–leucine–leucine–alanine (DELLA)–dependent manner ( 67 ). In addition, NPF4.6 regulates vasculature ABA import, and ABCG25 and DTX50 regulate vasculature ABA export ( 24 ).…”