Vein arrangement, density ... which are outgrowths produced by living plant cells surrounding a vessel to seal it off after wounding or pathogen invasion (Figure 8). Abiotic factors can be ...

Researchers have developed so-called microbial cell factories -- using E. coli and yeast -- to produce a special class of plant hormones, known as strigolactones, at unprecedented levels.

Vascular tissue in the midrib and veins Branches of the xylem ... products of photosynthesis to other parts of the plant. Air spaces between cells within the leaf For the diffusion of gases.