Tomato Shade Avoidance: Unraveling Internode Elongation and Hormonal Harmony

In a quest to unravel the intricate dance of plants with light, our journey begins with
the pivotal role of light and plant growth general introduction. The competition among
neighboring vegetation sparks the phenomenon of shade avoidance syndrome (SAS),
driven by far-red light enrichment. Armed with a foundation of molecular insights from
prior research on shade avoidance syndrome, our thesis sets sail into uncharted territory.
Chapter 1 delves into the shade avoidance syndrome (SAs) in tomato cultivars M82
and Moneymaker, dissecting cellular developmental plasticity under white light and
far-red supplemented conditions. Microscopy-based quantification zooms into the first
internode, revealing significant cellular anatomy responses, setting the stage for deeper
exploration in subsequent chapters.
Chapter 2 explores the molecular mechanism with tissue specific signally in SAS. A time
series RNAseq sheds light on auxin’s early role in internode elongation and identification
of transcription factors, paving the way for Chapter 4’s exploration of hormones,
identifying potential key regulators.
The hormonal dynamics take center stage in Chapter 4, as we probe into auxin,
gibberellins, and brassinosteroids during SAS. The study unveils complex interactions
governing stem elongation, highlighting the nuanced influence of auxin, while GA and
BR emerge as potent players. The intricate interplay of these hormones shapes plant
responses to shade, emphasizing their crucial roles.
Chapter 5 encapsulates a multidimensional exploration, examining cell expansion,
the regulatory roles of transcription factors, and the dynamics of shade avoidance
responses across 8 dicots. Pith elongation patterns, transcriptional regulation, and
motif distribution offer a nuanced understanding of conserved regions, showcasing the
interdisciplinary nature of plant biology.Our journey concludes with a spotlight on the
distribution of dissimilar transcription factors across plant families, paving the way for
future investigations.
In the final chapter, we cast a broad perspective on the constraints of RNAseq analysis,
hormone analysis, and evolutionary considerations. The discovery of a general conservation
pattern between pith-specific expression in far-red across diverse species and transcription
factor conservation opens avenues for deeper research. While our proposed linkage model
awaits further confirmation, this ongoing exploration promises to unveil the molecular
intricacies of plant responses to light, enriching our understanding of adaptation strategies.