Fig. 7
![Fig. 7](http://media.springernature.com/full/springer-static/image/art%3A10.1186%2Fs12870-022-03717-3/MediaObjects/12870_2022_3717_Fig7_HTML.png)
The contents of endogenous ALA (A), Proto IX (B), Mg-Proto IX (C) and heme (D) in cucumber seedlings. Values were mean ± SE (n = 3). Bars with different lowercase letters were significantly different by Tukey’s multiple range test (P < 0.05)