Hormonal interactions underlying parthenocarpic fruit formation in horticultural crops

Abstract

In some horticultural crops, such as Cucurbitaceae, Solanaceae, and Rosaceae species, fruit set and development can occur without the fertilization of ovules, a process known as parthenocarpy. Parthenocarpy is an important agricultural trait that can not only mitigate fruit yield losses caused by environmental stresses but can also induce the development of seedless fruit, which is a desirable trait for consumers. In the present review, the induction of parthenocarpic fruit by the application of hormones such as auxins (2,4 dichlorophenoxyacetic acid; naphthaleneacetic acid), cytokinins (forchlorfenuron; 6-benzylaminopurine), gibberellic acids, and brassinosteroids is first presented. Then, the molecular mechanisms of parthenocarpic fruit formation, mainly related to plant hormones, are presented. Auxins, gibberellic acids, and cytokinins are categorized as primary players in initiating fruit set. Other hormones, such as ethylene, brassinosteroids, and melatonin, also participate in parthenocarpic fruit formation. Additionally, synergistic and antagonistic crosstalk between these hormones is crucial for deciding the fate of fruit set. Finally, we highlight knowledge gaps and suggest future directions of research on parthenocarpic fruit formation in horticultural crops.

Plant hormones and neurotransmitter interactions mediate antioxidant defenses under induced oxidative stress in plants

“…SA also exerted a remedial effect on the performance of essential oils, mainly at 0.5 mM ( Fatima et al, 2022 ). Plant hormones and antioxidants play a vital role in fruit ripening, quality, and parthenocarpic fruit formation ( Irfan et al, 2021 ; Su et al, 2021 ; Sharif et al, 2022 ; Tayal et al, 2022 ). Under water-stressed conditions, foliar-applied SA reduced MDA and H 2 O 2 contents and ion leakage and increased SOD and POX activities under all irrigation regimes ( Biareh et al, 2022 ).…”

Auxin Coordinates Achene and Receptacle Development During Fruit Initiation in Fragaria vesca

“…Multiple phytohormones participate in fruit set, and their crosstalk ensures the precise regulation during this process (Sharif et al, 2022 ). Based on p < 0.05 and |log2(fold change)| > 1.5, 62 DEGs participating in the phytohormone pathway were screened out as pollination or auxin-responsive genes in achenes or receptacles ( Figure 7A ).…”

“…Fruit set can be induced by both pollination-dependent and -independent manners, and the dynamic hormone distribution plays key roles in fruit set (Fenn and Giovannoni, 2021 ; Sharif et al, 2022 ). Auxin, which is mostly accumulated in the fertilized achene, seems to play a central role in fruit set.…”

“…These findings have been applied in both horticulture and agriculture in order to produce seedless and high-quality fruits. The regulatory mechanisms of phytohormones in fruit set attracted intense interest during past years (Sharif et al, 2022 ).…”

Cross-talk between the cytokinin, auxin, and gibberellin regulatory networks in determining parthenocarpy in cucumber

“…Cucumber has emerged as a model organism for understanding parthenocarpy because of its abundant parthenocarpic germplasm. Fruit set without pollination in a gynoecious genotype with only female flowers has enabled a manifold increase in cucumber productivity, giving it high potential as an economic crop for protected cultivation (Sharif et al, 2022).…”