ABC	ATP-binding cassette
BLAST	Basic Local Alignment Search Tool
bp	base pairs
CDK	cyclin-dependent kinases
CDKB	class B of cyclin-dependent kinases
cDNA	complementary deoxyribonucleic acid
CDS	coding sequence
cll	columella
crh	curled root hair
cv.	cultivar
CYC1	cyclin 1
DNA	deoxyribonucleic acid
DNase	deoxyribonuclease
dpi	day/days postrhizobial inoculation
ER	endoplasmic reticulum
GUS	β-glucuronidase
IAA	indole-3-acetic acid
lc	lateral root cap
LECA	lightweight expanded clay aggregate
NCBI	National Center for Biotechnology Information
nc	nodule cortex
np	nodule primordium
nvb	nodule’s vascular bundle
OD	optical density
p	probability value
PAT	polar auxin transport
pc	procambium
PCR	polymerase chain reaction
PEO-IAA	α-(phenyl ethyl-2-one)-indole-3-acetic acid
PIN	PIN-formed protein
PPFD	photosynthetic photon flux density
prc	meristematic primary root cortex
qPCR	quantitive polymerase chain reaction
RAM	root apical meristem
rc	root primary cortex
RNA	ribonucleic acid
RT-PCR	reverse transcriptase polymerase chain reaction
SE	standard error
v.	version
vs.	versus
w/v	weight per volume