Table 1 Important genes related to trichome development in plants

GL1

Positive;

Negative

Regulate initiation of trichome, the mutant results in trichome defect, but overexpression leads to a reduction in trichome.

[33, 34]

TTG1

Positive

Regulate the initiation of trichome, the mutant results in trichome defect.

[35, 36]

GL3

Positive

Regulates the initiation of trichome, and the mutant results in fewer trichomes.

[37, 38]

GL2

Positive

Regulates epidermal cell fate, the mutant results in fewer trichomes, and most of them are not branched.

[39]

EGL3

Positive

Function redundant with GL3, and gl3/egl3 double mutants show no trichome.

[40]

MYB23

Positive; Negative

myb23 single mutants exhibit reduced trichome branching but no obvious effect in trichome initiation and overexpression of the MYB23 gene causes ectopic trichome initiation. MYB23 has functional redundancy with GL1.

[41]

TRY

Negative

Trichome of mutant grows in clusters and branches increase.

[42]

CPC

Negative

The mutant exhibits reduced number of trichome and clustered trichome.

[43]

ETC1

Negative

ETC1 overexpression causes a reduction in trichome formation, etc1 single mutant has no significant phenotype. Function of ETC1 is partially redundant with TRY and CPC.

[44]

ETC2

Negative

ETC2 overexpression results in the suppression of trichomes, etc2 single mutant shows an increase in trichome number on leaves and petioles. ETC2 acts redundantly with TRY and CPC in trichome patterning.

[44]

TT8

Positive

Particularly important for marginal trichome development, no trichomes could be detected at the margin of young developing tt8 leaves in the absence of exogenously added hormones.

[45]

MYC-1

Positive

MYC1 is a positive regulator of GL2, the mutant with defect in trichome, and root hair pattern formation.

[46]

MYB5

Positive

Constitutive expression of MYB5 resulted in the formation of smaller trichomes and ectopic trichomes and a reduction in total leaf trichome numbers and branching, the mutant displayed minimal changes in trichome morphology.

[47]

GIS

Positive

Regulates the differentiation of epidermal cells and inflorescences, and the trichome of the mutant is reduced.

[48]

RHL2

Positive

Regulate trichome nucleus replication, regulate trichome morphology.

[49]

ICK/KRP

Positive

Regulate trichome nucleus replication.

[50]

HYP6

Positive

The mutant has a small number of trichome branches and intranuclear replication (8C).

[51]

ZWI

Positive

The mutant has a small number of trichome branches.

[52]

SAD2

Positive

Regulate the initiation of trichome, mutant sad2 presents a phenotype with reduced trichome.

[53]

SIM

Negative

Inhibits mitotic cycle, its mutants exhibit multicellular trichome, while other morphologies are normal.

[54]

KAK

Negative

The mutation of KAK resulted in excessively branched trichome and the nuclear DNA content reaches 64C.

[55]

SPY

Negative

SPY is a gibberellin signaling repressor and the SPY deletion mutant has increased trichome branching.

[4, 7]

CPR5

Negative

The cpr5 mutant has a small number of trichome branches, the trichome volume decreases, and the intranuclear replication cycle stays at the end of the second cycle.

[56]

RBR1

Negative

Through its interaction with members of the E2F family of transcription factors, regulates the balance between cell division and the endocycle, and the conditional inactivation of RBR1 results in trichomes with altered morphologies, which include more branches.

[57]

HDG11

Negative

HDG11 plays negative regulatory roles in trichome branching and hdg11 mutants result in excess branching of trichomes.

[58]

GLH

Positive

GLH can induce the formation of papillae in the late stage of development, glh mutants showed defects in papillae formation and reduces in cellulose content.

[59]

TBR

Positive

TBR is required for secondary wall cellulose synthesis, the Arabidopsis tbr has severely reduced crystalline cellulose in trichomes and reduced trichome density, altered trichome shape and surface appearance, lack of trichome papillae and basal cells, altered stomata shape, and altered patterns of callose deposition.

[60]

NOK

Positive

The noeck (nok) mutant has trichomes with increased branching and a glassy transparent appearance but displays no increase in nuclear DNA content.

[61]

MIXTA

Positive

Overexpression of MIXTA led to the growth of a large number of trichomes on cotyledons, leaves, and stems in tobacco.

[62]

CotMYB

Positive

Overexpression of CotMYB does not change its phenotype in Arabidopsis but increases the number of tobacco trichomes.

[62]

GaMYB2

Positive

Cotton fibrin GaMYB2 not only regulates the leaf and stem trichome development of the Arabidopsis gl1 mutant, but also induces the formation of seed trichome.

[63]

AnnGh3

Positive

Overexpression of AnnGh3 isolated from cotton in Arabidopsis resulted in a significant increase in leaf trichome density and length.

[64]