Figure 6.

OsMKK10-2 and OsWRKY31 are involved in PAMP regulation of defense and auxin pathways. A) Changes of OsPIN2pro:GUS expression pattern and primordia formation by chitin treatment. Five-day-old OsPIN2pro:GUS seedlings were treated with 200 µg mL⁻¹ chitin for 12 h and stained at 37 °C for 4 h. Values are means ± SD of three biological replicates. B) Chitin and flg22 suppress auxin transport. Seven-day-old ZH17 seedlings grown in the dark were treated with 1 µM flg22 or 200 µg mL⁻¹ chitin for 12 h, and then the coleoptiles were collected for PAT assay as described in Fig. 4. Error bars represent standard deviation of five replicate experiments. Significance test was evaluated using the Student's t-test (***, P < 0.001). Suppression of OsPIN2C) and DR5D) promoter activities by MeJA and SA. Five-day-old OsPIN2pro:GUS, DR5:GUS, and DR5:GUS w31ko seedlings were treated with MeJA (200 µM), SA (500 µM), or in combination with IAA (1 µM), and the mock received the same amount of DMSO at 28 °C for 12 h. Representative GUS staining images of OsPIN2pro:GUS primary roots stained at 37 °C for 4 h, and DR5:GUS and DR5:GUS w31ko staining at 37 °C for 1 h. Bar = 0.5 mm C and D). E) Expression of SA (OsWRKY76), JA (OsLOX2), and IAA (OsPIN2) marker genes in roots. Five-day-old DR5:GUS seedlings were treated with phytohormones as described in D). Gene expression was determined by RT-qPCR analysis using OsUBQ as the reference. Data are means ± SD of three independent treatments. Values marked with different letters indicate statistically significant differences as analyzed by the SPSS software (Duncan's multiple range test, α = 0.05).