Fig. 7: Functional verification of zmmax1b mutants upon HS.

A–C The primary root phenotypic (A) and apical microstructure (B) of Mo17 and B73 of maize after 4 days germination and quantitative of cortical cell area (C) in apical sections of Mo17 and B73 maize lines. The red box points to amplify the phenotypic of the root apical. Statistical significance was tested using a two-tailed t test (n = three biological replicates; mean ± SD; ***represents p < 0.001). D The phenotypic of Mo17 and B73 of maize seedlings upon HS (Bars = 10 cm). E The relative injury rate of the maize seedlings after HS for Mo17 and B73 (n = three biological replicates; mean ± SD; **represents p < 0.01, ***represents p < 0.001). F The correlation of root cortex size and plant relative injured rate of inbred lines after HS. G Sequence alignment (partial) of the ZmMAX1b gene in B73 wild-type (WT) and zmmax1b-1 mutant plants. The blue arrow marks the mutation site in the zmmax1b-1 mutant. H–J The primary root apical phenotypic (H) and microstructure (I) of B73 and zmmax1b of maize after 4 days germination and quantitative of cortical cell area (J) in apical sections in zmmax1b mutants (n = three biological replicates; mean ± SD; * represents p < 0.05). Statistical significance was tested using a two-tailed t test. The red box points to the amplified phenotypic of the root apical (Bars = 1 cm). K The mRNA relative expression of ZmMAX1b gene in B73 and zmmax1b−1 mutants (n = three biological replicates; mean ± SD; ***represents p < 0.001). Statistical significance was tested using a two-tailed t test. L, M The phenotypic (L) and relative injury rate (M) of B73 and zmmax1b-1 seedlings under HS (Bars = 10 cm) (n = three biological replicates; mean ± SD; **represents p < 0.01; ***represents p < 0.001). N A proposed model for cortex’s functions in response to HS. One-way ANOVA and Bonferroni multiple comparison tests were used to test for statistical significance in (E, M). Source data and exact p-values are provided in the Source Data file.