Homeobox genes encoding WOX transcription factors in the flowering parasitic plant Monotropa hypopitys

Abstract

The formation and maintenance of plant stem cell populations are controlled by the WOX family of homeobox-containing transcription factors. The evolution of WOX genes is considered to be one of the main reasons for flower morphology and plant architecture diversity. The stem cell regulation mechanism is considered to be conserved among flowering plants and most thoroughly studied in Arabidopsis thaliana as a model. The angiosperms morphological diversity implies that there are species-specific features inherent to this mechanism, while the basic signaling is maintained. The unique flowering achlorophyllous mycoheterotrophic plant Monotropa hypopitys obtains nutrients from the tree roots through the mycorrhizal symbiosis. In inductive conditions, the reproductive stem with bracts and an inflorescence at the top is developed from an adventitious root bud. Like other plants, M. hypopitys forms the inflorescence, flower and root meristems, presumably using conserved mechanisms regulating stem cell niche. The study of M. hypopitys homeobox genes should contribute to the knowledge about the function of WOX transcription factors and further understanding of the stem cells control mechanisms in mycoheterotrophic species. The aim of the present study was to analyze M. hypopitys root, bracts and flower transcriptomes obtained from two individual flowering plants. In total, five WOX genes have been identified and characterized by their structure, phylogeny, expression pattern, and possible functions. The assumption is that the MhyWUS1 and MhyWUS2 genes maintain the stem cell population in the inflorescence and flower meristems, MhyWOX13 has a role in the control of root stem cell niche, seed pod formation, flowering initiation, and basic cellular processes, MhyWOX4 functions in the Формирование и поддержание популяций стволовых клеток растения контролируются гомеодомен-содержащими факторами транскрипции семейства WOX. Эволюция гомеобоксных генов, кодирующих данные белки, считается одной из главных причин многообразия форм цветка и морфологии растения в целом. Меха-низм регуляции ниш стволовых клеток в апикальных меристемах признан консервативным для цветковых растений разных видов и наиболее подробно исследован на модели Arabidopsis thaliana. Морфологическое разнообразие покрытосеменных подразумева-ет наличие особенностей этого механизма, присущих отдельным видам, при сохранении основных сигнальных путей. Уникальный представитель покрытосеменных бесхлорофилльный микоге-теротроф подъельник Monotropa hypopitys получает питатель-ные вещества от корней деревьев через микоризный симбиоз. В индук тивных условиях адвентивные репродуктивные почки на корнях M. hypopitys выпускают цветонос с прицветниками и соцве-тием на конце. M. hypopitys так же, как и другие растения, форми-рует меристемы соцветия, цветка и корня, вероятно, используя консервативные пути регуляции ниш стволовых клеток. Изучение гомеобоксных генов такого растения расширит знания о важных эволюционных факторах транскрипции WOX и позволит лучше представлять механизмы...

Genome-Wide Association Studies for Sex Determination and Cross-Compatibility in Water Yam (Dioscorea alata L.)

“…Four gene/protein families were found on chromosomic regions associated with ACR: Homeobox domain (WOX genes); Helix-turn-helix motif (LEAFY (LFY) protein); NAC domain (NAC TFs, MtNAM); and Zinc finger CCHC-type protein (Mt-Zn-CCHC gene). Previous reports have demonstrated the role of these families in either floral morphology, flowering initiation, differentiation of egg cells and zygotes, seed pod formation, translocation toward fruit under stress conditions, regulation of floral organ identity or seed size in Monotropa hypopitys [ 36 ], Arabidopsis thaliana [ 37 ], Citrullus lanatus [ 38 ] or Medicago truncatula [ 39 , 40 ].…”

Transcription Factor McHB7 Improves Ice Plant Drought Tolerance through ABA Signaling Pathway

“…For example, the rice WUSCHEL-related homeobox genes participate in plant reproductive organ development, hormone signaling, and abiotic stress response [8]. In pinesap (Monotropa hypopitys), MhyWOX13 plays a role in the root stem cell niche, seed pod formation, flower initiation, and basic cellular processes [9]. In apple, MdHOXs have been shown to be involved in abiotic stress response, as MdHOXs were upregulated in the leaves and roots after treatments with cold, salt or abscisic acid (ABA) [10].…”