Microscopic Characterization of a Transposon-Induced Male-Sterile, Female-Sterile Mutant in Glycine max L.

Abstract

Premise of research. A male-sterile, female-sterile mutant was discovered in a w4-m mutable line of Glycine max L. The mechanism of its sterility was not well understood. Therefore, different cytological and microscopic techniques were undertaken to better understand the process of mutant phenotype development. Molecular research indicated that mer3 was responsible for the sterility. Methodology. Macro images were collected of whole plants, flowers, anthers, pods, and ovules. Chromosome spreads from anthers at various meiotic stages were examined. Confocal scanning laser microscopy using optical sectioning was utilized on whole anthers and ovules at various developmental stages. Whole mature anthers and isolated pollen images were collected and studied with SEM. Pivotal results. In observations of the mutant, male cell development was found to begin normally and then digresses at metaphase I of meiosis, when abnormal segregation of chromosomes with reduced bivalent formation was observed. It was the abnormal formation of univalents and bivalents that led to male sterility. On the female side, the progression of development was arrested in the megagametophyte stage likely because of abnormal meiosis, leading to ovule abortion and female sterility. Conclusions. The G. max male-sterile, female-sterile mutant was shown to have the same phenotype of mer3 sterility already shown in Arabidopsis, rice, yeast, and some animal systems.

Comparative analysis of the transcriptome during single-seed formation of Castanea henryi: regulation of starch metabolism and endogenous hormones

“…The main physiological functions of CKs are the promotion of cell division and regulation of cell differentiation, delaying aging, and the degradation of proteins and chlorophyll. CKX (5,1), AHK (1, 3, 1.1), and ARR17 were upregulated in SO1 and SO2. CKX5 was highly transcribed in SO1 and SO2 (FPKM value of > 1300).…”

“…Although each ovule has the potential to be fertilized until it forms viable embryos, obstacles arising during sexual reproduction can prevent some ovules from developing. The occurrence of ovule abortion may be affected by physiological, biochemical, embryological, environmental, and molecular factors, including male sterility [ 4 ], female sterility [ 5 ], poor pollination or fertilization [ 6 ], temperature [ 7 ], and water [ 8 ]. Consequently, understanding the mechanisms of ovule development is of great importance from both scientific and economic perspectives.…”