Exploring the role of 28-homobrassinolide in regulation of temperature induced clastogenic aberrations and sugar metabolism of Brassica juncea L.

The present research primarily focuses on Brassica juncea's physiological and cytological responses to low and high temperature stress at 4 °C and 44 °C respectively, along with elucidating the protective role of 28-Homobrassinolide (28-homoBL). Cytological investigations performed in floral buds of Brassica juncea L. under temperature (24, 4, 44 °C) stress conditions depict the presence of some abnormalities associated with cytomixis such as chromosome stickiness or agglutination, pycnotic nature of chromatin, irregularities in spindle formation, disoriented chromatins, and non-synchronous chromatin material condensation in Brassicaceae family that subsisted at diploid level (2n = 36). Spindle abnormalities produce various size pollen grains such as sporads micronuclei at some stages of microsporogenesis, polyads, triads, dyads that irrupted the productiveness of pollen grains. Furthermore, sugars play an imperative role in protecting plants under stress besides being energy sources. Therefore, the present study revealed accumulation of total soluble sugars (TSS), with 28-homoBL treatment which pinpoints protective role of 28-homoBL under temperature stress. Sugar profiling was done by using high-performance liquid chromatography (HPLC) which helped in analyzing different sugars both quantitatively and qualitatively under 28-homoBL and temperature stress conditions. The results indicate that the 28-homoBL treatment substantially enhances plant tolerance to heat stress, as evident by higher mitotic indices, fewer chromosomal abnormalities, and significantly more sugar accumulation. The findings of the study acknowledge the potential of 28-homoBL in inducing temperature stress tolerance in B. juncea along with improving the metabolic stability thereby implying application of 28-homoBL in crop strengthening under variable temperature conditions.
Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
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