In an automated vertical farming facility growing butterhead lettuce, a sensor malfunction leads to nutrient imbalances in the hydroponic system.
The automated sensors measure the translocation of organic solutes, such as sucrose, from the leaves to the roots. Name the specialized vascular tissue responsible for this transport.
A laboratory analysis of the nutrient reservoir reveals a critical deficiency of magnesium ions (Mg2+\text{Mg}^{2+}Mg2+). Within two weeks, the lettuce crop exhibits interveinal chlorosis (yellowing of leaves) and severely stunted growth. Explain how a deficiency of magnesium ions results in the stunted growth of these plants.