Current Advances in Molecular Mechanisms and Physiological Basis of Panicle Degeneration in Rice

Abstract

Panicle degeneration, also known as panicle abortion, is a serious defect and causes heavy losses to reproductive yield in cereals. Several mutants have been reported to display the phenotype of spikelet abortion in rice. Recent findings have resulted in significant breakthroughs, but comprehensive understanding about the molecular pathways and physiological basis of panicle degeneration still remain a dilemma. In this review, we have summarized all the responsible genes and mechanisms underlying the panicle development with a special focus on degeneration. Here, we hypothesized a model by using knowledge and coherent logic in order to understand the molecular regulation of panicle degeneration. In addition to this, we included all the previous discoveries, schools of thoughts, ancient working theories, and crosstalk of phytohormones and provided new insights for future studies.

Keywords: panicle degeneration; phytohormones; programmed cell death; source limitation.

Figure 1

Hypothesized working model for an understanding of the molecular and physiological mechanisms governing panicle development and degeneration. The black arrows show the direct association of specific factors with the panicle degeneration. The dotted red arrows show the regulation of panicle degeneration by controlling the expression of genes that are mentioned above the arrow. The T-head arrows show the negative association of genes with panicle degeneration. The question mark reveals the elucidation mechanism is not reported in studies yet.