Cellular anatomy of tomato stems in response to far-red light 2 37 R:FR=2 R:FR=0.20 R:FR=0.11 0 50 100 150 Stem length(mm) c b a R:FR=2 R:FR=0.20 R:FR=0.11 0 20 40 60 Internode1 length(mm) c b a R:FR=2 R:FR=0.20 R:FR=0.11 0 1 2 3 4 Internode diameter (mm) b a ab (a) (b) (c) Figure 2.10. Moneymaker responses to different R:FR ratios. The data includes measurements of (a) stem length, (b) internode 1 length, and (c) internode 1 diameter. The data are presented as mean ± SEM, and different letters indicate significant differences between treatments based on ANOVA analysis with Tukey’s post hoc test (P<0.05). There were 18 plants per local treatment, and the experiment was repeated three times. 2.2.4 FR induced responses in multiple cell types in the stem We found that supplemental FR induced many phenotypic responses, and the stem elongation was the most striking one. However, how the cellular anatomy changes during the FR-induced stem elongation has not been previously fully characterized and we wanted to address this gap in knowledge. We selected the first internode for cellular anatomy phenotyping because it was the only internode that was present at the start of the FR light day treatment, 14 days after sowing, and it had the most significant response among all internodes: it had the lowest p-value and it contributed most to the elongation in stem (Figure 2.5b). We prepared cross and longitudinal sections at the halfway point of the internode. Cell types (Figure 2.11) were characterized according to the descriptions by Taiz et al. (2010) and plant anatomy website (https://www.kbg.fpvai.ukf.sk/studium_ materialy/morfologia_rastlin/index.html), summarized as: 1) Epidermis: the outermost one layer of stem; 2) hypodermis: the layer beneath epidermis with a relatively similar structure as epidermis (Murray, 1983); 3) Collenchyma: the thicker, secondarily formed cell layer next to the epidermis and hypodermis; 4) Parenchyma: elongated spongy cells with regular shape between interfascicular cambium and collenchyma; 5) Interfascicular cambium: cells linking the vascular bundles with remarkably thicker cell walls; 7) Pith: big spongy and round cells in the middle of the stem. In the vasculature we measured the two main tissues: 8) Xylem: complex tissues that consists of different types of cells,
RkJQdWJsaXNoZXIy MTk4NDMw