Table 1. Node centrality analysis identifies 5 categories of nodes in the ABA-induced stomatal closure network.
| Category | Node count | Nodes |
|---|---|---|
| Source nodes other than ABA | 22 | ABH1, ARP Complex, CPK6, CPK23, DAGK, ERA1, GAPC1/2, GCR1, GEF 1/4/10, GTP, MRP5, Nitrite, NADPH, NAD+, NtSyp121, PC, PtdInsP3, PtdInsP4, RCN1, SCAB1, Sph, SPP1 |
| Transducers | 30 | AGB1, AGG3, AtRAC1, Aquaporin (PIP2;1), AnionEM, Ca2+ ATPase, cGMP, CPK3/21, DAG, Depolarization, HAB1, H+ ATPase, InsP3, InsP6, KEV, K+ Efflux, Malate, MPK9/12, Microtubule Depolymerization, NOGC1, PEPC, PI3P5K, PtdIns(3,5)P2, PtdIns(4,5)P2, PP2CA, RCARs, ROP11, TCTP, V-ATPase, V-PPase |
| Integrators outside of the SCC | 4 | H2O Efflux, KOUT, SLAC1, SLAH3 |
| Intermediate SCC members | 15 | 8-nitro-cGMP, ABI2, ADPRc, cADPR, GHR1, GPA1, NO, OST1, NIA1/2, PLC, PLDα, PLDδ, QUAC1, SPHK1/2, Vacuolar Acidification |
| Integrators inside the SCC | 5 | Actin Reorganization, CaIM, CIS, RBOH, S1P/PhytoS1P |
| Key nodes | 5 | ABI1, Ca2+c, PA, pHc, ROS |
The first column identifies the categories, the second column indicates the node count, and the third column gives the node list in each category. Source nodes other than ABA (first row) only have 1 or 2 out-going edges (likely because of the scarcity of knowledge about them) and have a betweenness centrality of zero (because they do not mediate any paths). Transducers (second row) have low in- and out-degree and low betweenness centrality; they may belong to any component of the network. Membership in the SCC tends to correlate with a high betweenness centrality. For example, 4 integrators in the out-component of the network have a low betweenness centrality, while the 5 integrators inside the SCC have a moderate to high betweenness centrality. Fifteen nodes of the SCC have moderate in- and out-degree and moderate-to-high betweenness centrality; we refer to these nodes as intermediate SCC members. The nodes in the last row are the most central nodes according to all 3 measures. We did not categorize the signal node ABA, the output node Closure, or the alternate sink node ROP10.
Abbreviation: SCC, strongly connected component. All other abbreviations are explained in S3 Table.