Expression pattern of ABA metabolic and signalling genes during floral development and fruit set in sweet cherry

Pan

et al. 2020

Plants

Fruit size and shape are important qualities and yield traits in cucumber (Cucumis sativus L.), but the factors that influence fruit size and shape remain to be explored. In this study, we investigated the dynamic changes of fruit size and shape from the aspects of morphology, cellular levels and endogenous hormones for nine typical cucumber inbred lines. The results show that fruit length had a strong positive correlation to the cell number in the longitudinal section of fruit throughout the four stages of 0, 6, 12, and 30 DAA (days after anthesis). However, the significant negative correlations were found between fruit length and the fruit cell size at 12 and 30 DAA. Furthermore, fruit diameter was positively correlated to the cell number in the cross section at all the investigated fruit growth stages. The indole-3-acetic acid (IAA) content showed significant positive correlations to the fruit length at all fruit growth stages of −6, −3, 0, 3, 6, 9 and 12 DAA, but IAA content and fruit diameter showed significant negative correlations for all the stages except for at −6 DAA. The trans-zeatin riboside (tZR), zeatin (ZT), gibberellic acid (GA3) and jasmonic acid (JA) content had a positive or negative correlation with fruit length or diameter only at certain stages. Neither fruit length nor diameter had significant correlations to abscisic acid (ABA) content. These results indicate that variations in fruit size and shape of different cucumber inbred lines mainly result from the differences in fruit cell number and endogenous IAA content. The present work is the first to propose cucumber fruit size and shape changes from the combined aspects of morphology, cellular levels, and endogenous hormones.

Section: Discussionmentioning

confidence: 99%

Cucumber Fruit Size and Shape Variations Explored from the Aspects of Morphology, Histology, and Endogenous Hormones

Pan

et al. 2020

Plants

“…The results revealed that the expression level of PaPP2C1/2/3 were increased in young fruit and ovary while PaPP2C3/4 were highly expressed in the stamen. On the other hand, 6 PaSnRK2s showed varied expression profiles such as PaSnRK2.1/2.2/2.4 were expressed greatly in young fruit and ovary and PaSnRK2.1/2.3 in the stamen ( Leng et al, 2018 ). PaSnRK2.1/2.2/2.4 were highly expressed in the ovary and young fruit, while PaSnRK2.1/2.3 were highly expressed in the stamen.…”

Section: Abscisic Acid Signal Transduction and Its Transcriptional Re...mentioning

confidence: 99%

Abscisic Acid: Role in Fruit Development and Ripening

Gupta¹,

Wani

Razzaq

et al. 2022

Front. Plant Sci.

Abscisic acid (ABA) is a plant growth regulator known for its functions, especially in seed maturation, seed dormancy, adaptive responses to biotic and abiotic stresses, and leaf and bud abscission. ABA activity is governed by multiple regulatory pathways that control ABA biosynthesis, signal transduction, and transport. The transport of the ABA signaling molecule occurs from the shoot (site of synthesis) to the fruit (site of action), where ABA receptors decode information as fruit maturation begins and is significantly promoted. The maximum amount of ABA is exported by the phloem from developing fruits during seed formation and initiation of fruit expansion. In the later stages of fruit ripening, ABA export from the phloem decreases significantly, leading to an accumulation of ABA in ripening fruit. Fruit growth, ripening, and senescence are under the control of ABA, and the mechanisms governing these processes are still unfolding. During the fruit ripening phase, interactions between ABA and ethylene are found in both climacteric and non-climacteric fruits. It is clear that ABA regulates ethylene biosynthesis and signaling during fruit ripening, but the molecular mechanism controlling the interaction between ABA and ethylene has not yet been discovered. The effects of ABA and ethylene on fruit ripening are synergistic, and the interaction of ABA with other plant hormones is an essential determinant of fruit growth and ripening. Reaction and biosynthetic mechanisms, signal transduction, and recognition of ABA receptors in fruits need to be elucidated by a more thorough study to understand the role of ABA in fruit ripening. Genetic modifications of ABA signaling can be used in commercial applications to increase fruit yield and quality. This review discusses the mechanism of ABA biosynthesis, its translocation, and signaling pathways, as well as the recent findings on ABA function in fruit development and ripening.

“…In cherry, ABA and its signal transduction related gene PaSnRK2.1/2.2/2.4 are highly expressed in the ovary and young fruit. This indicates ABA plays an important role in fruit development [32]. In Arabidopsis, ABA has also been shown to act as a switch for flower development.…”

Section: Discussionmentioning

confidence: 97%

miRNA and mRNA studies reveal pollination activates hormonal signaling and increases fruit set in the apomictic tree Zanthoxylum bungeanum Maxim

Fei

Yao

Wei

2019

Preprint

Background Apomixis is a form of reproduction that does not involve fertilization of female by male gametes but instead produces offspring from the female parent directly. The progeny of apomixis is genotypically identical to the female parent and so maintains any elite traits of the female parent. Apomixis has considerable potential in genetic plant breeding. However, the mechanism of apomictic reproduction remains unclear. Zanthoxylum bungeanum is an apomictic plant. Studies on miRNAs, mRNAs, hormone changes and fertilization process of the pollinated and non-pollinated materials of Zanthoxylum bungeanum allows screening of the important regulatory factors of the apomictic process at both physiological and molecular levels. This information should be of considerable help in understanding the mechanism of apomixis in this species.Results Our results show that Zanthoxylum bungeanum pollen can germinate on the stigma, and that the pollen tube can extend to the ovary wall after two days but that it then degenerates about the fifth day and before reaching the egg cell. So fertilization does not occur. Nevertheless, pollination did increase fruit set from 74.12% (unpollinated) to 89.31% (pollinated). The reproductive mode of the Zanthoxylum bungeanum cultivar ‘Hancheng Dahongpao’ was identified as obligate apomixis. Enrichment analysis of differential genes indicates that pollination activates genes involved in the synthesis of ABA, IAA, GA3 and JA, and that genes related to asexual development, genes involved in flower development, and transcription factors are also activated. RT-qPCR verification shows that the relative expression levels of mRNAs and miRNAs related to hormone signaling pathways and flower development were negatively correlated. Also, that miRNA is an important factor influencing hormone regulation after pollination of this apomictic species. The contents of ABA, IAA, GA3 and JA were all significantly increased following pollination.Conclusions In general, although pollination does not result in fertilization in this species, it does activate mRNAs and miRNAs which serve as signals to activate the anabolic pathways for ABA, IAA, GA3 and JA. Increased levels of these hormones result in increased fruit set.