Number coordination of stomata and minor vessels and its implication
We also found strong covariation between terminal xylem vessel number and stomatal number per plant (Fig. 5a; Table 1). That is: in order to ensure the balance between liquid- and vapour-phase water conductance, convergent scaling exists between total stomatal area and xylem area, both at the entire plant and at individual leaf level; and this area-scaling pattern was driven by the covariation of stomata numbers and minor vessel numbers per plant.
These findings provide empirical support for, as well as a better functional understanding of the xylem structure models and have broad implications for integrating xylem widening (Anfodillo et al. , 2006, Olson, Anfodillo, Rosell, Petit, Crivellaro, Isnard, León‐Gómez, Alvarado‐Cárdenas & Castorena, 2014, Zhong et al. , 2019) and stomatal distribution; these linkages are illustrated in Fig. 1. Further studies on plant water relations should incorporate the transport mechanism of water from the minor vein xylem vessels to stomata with xylem architecture.