Fruit Indehiscence Caused by Enhanced Expression of NO TRANSMITTING TRACT in Arabidopsis thaliana

Abstract

In flowering plants, fruit dehiscence enables seed dispersal. Here we report that ntt-3D, an activation tagged allele of NO TRANSMITTING TRACT (NTT), caused a failure of fruit dehiscence in Arabidopsis. We identified ntt-3D, in which the 35S enhancer was inserted adjacent to AT3G-57670, from our activation tagged mutant library. ntt-3D mutants showed serrated leaves, short siliques, and indehiscence phenotypes. NTT-overexpressing plants largely phenocopied the ntt-3D plants. As the proximate cause of the indehiscence, ntt-3D plants exhibited a near absence of valve margin and lignified endocarp b layer in the carpel. In addition, the replum was enlarged in ntt-3D mutants. NTT expression reached a peak in flowers at stage 11 and gradually decreased thereafter and pNTT::GUS expression was mainly observed in the replum, indicating a potential role in fruit patterning. NTT:GFP localized in the nucleus and cytoplasm. FRUITFULL (FUL) expression was downregulated in ntt-3D mutants and ntt-3D suppressed upregulation of FUL in replumless mutants. These results indicate that NTT suppresses FUL, indicating a potential role in patterning of the silique. In seed crops, a reduction in pod dehiscence can increase yield by decreasing seed dispersal; therefore, our results may prove useful as a basis to improve crop yield.

GhWIP2, a WIP zinc finger protein, suppresses cell expansion in Gerbera hybrida by mediating crosstalk between gibberellin, abscisic acid, and auxin

“…Previous studies show that AtWIP2/NTT localize in the nucleus (Appelhagen et al ., ) or in both the nucleus and cytoplasm (Chung et al ., ). Additionally, AtWIP2 forms a homodimer outside of the nucleus and functions mainly as a transcriptional activator (Marsch‐Martinez et al ., ).…”

“…Indeed, similar phenotypes related to cotyledons and seedling growth were found in GhWIP2OE Arabidopsis and AtWIP2/NTT gain‐of‐function plants. Both of them showed narrow cotyledons and stunted growth (Chung et al ., ) (Figs S6, S7). This means GhWIP2 and AtWIP2/NTT may share similar function.…”

Genetic and signalling pathways of dry fruit size: targets for genome editing‐based crop improvement

“…Plant‐specific DOF‐ type (DNA‐binding with one finger) transcription factors control various biological processes, of which the Arabidopsis dof4.2 mutant showed increased silique length and seed yield (Zou et al , ). The Arabidopsis NO TRANSMITTING TRACT ( NTT ) gene encodes a C2H2/C2HC zinc finger transcription factor that is specifically expressed in the transmitting tract and responsible for replum development (Chung et al , ). NTT loss function in Arabidopsis leads to reduced male fertility, seed set and silique length (Marsch‐Martínez et al , ).…”

BnLATE, a Cys2/His2-Type Zinc-Finger Protein, Enhances Silique Shattering Resistance by Negatively Regulating Lignin Accumulation in the Silique Walls of Brassica napus

“…Even conserved partial valve tissues developed into valve margin-like tissues (including lignified and dehiscence zone-like cell types), or formed into narrow files of replum cells that resemble those in the valve margin. Furthermore, seed development was reduced through valve elongation restrained after fertilization, especially in the basal part of the fruit due to a lack of coordinated growth of the fruit tissues, and resulted in yield failure [10, 12, 17–19]. In this study, overexpression of BnLATE resulted in less lignification in the replum, valve layer and dehiscence zone of yellowing silique in B .…”

“…Recently, Crawford, Ditta [16] reported that NO TRANSMITTING TRACT ( NTT ), a C 2 H 2 /C 2 HC-type zinc finger protein, plays a role in the differentiation of the transmitting tract in the carpels of Arabidopsis thaliana . Chung, Lee [17] showed that an activation-tagged allele of NTT ( ntt-3D) exhibited a silique indehiscence phenotype, and lacked lignified cells in the valve margin. However, these mutants, which were silique shattering-resistant, had reduced valve elongation after fertilization and substantially reduced seed development, especially in the basal part of the fruit due to a lack of coordinated growth of the fruit tissues, resulted in crop failure [10, 12, 17–19].…”