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The Associative Changes in Scutellum Nuclear Content and Morphology with Viability Loss of Naturally Aged and Accelerated Aging Wheat ( Triticum aestivum ) Seeds

View Article: PubMed Central - PubMed

ABSTRACT

Timely prediction of seed viability loss over long-term storage represents a challenge in management and conservation of ex situ plant genetic resources. However, little attention has been paid to study the process of seed deterioration and seed aging signals under storage. An attempt was made here to investigate morphological and molecular changes in the scutellum and aleurone sections of naturally or artificially aged wheat seeds using TUNEL assay and DAPI staining. Twelve wheat genotypes or samples exposed to natural ageing (NA) or accelerated ageing (AA) were assayed and these samples had germination rates ranging from 11 to 93%. The assayed samples showed substantial changes in scutellum, but not aleurone. The nuclei observed in the majority of the scutellum cells of the NA seed samples of lower germination rates were longer in size and less visible, while the scutellum cell morphology or arrangement remained unchanged. In contrast, longer AA treatments resulted in the loss of scutellum cell structure, collapse of cell layers, and disappearance of honey comb arrangements. These nuclei and structural changes were consistent with the DNA assessments of nuclear alternations for the selected wheat samples. Interestingly, the sample seed germination loss was found to be associated with the reductions in the scutellum nuclear content and with the increases in the scutellum nuclei length to width ratio. These findings are significant for understanding the process of wheat seed deterioration and are also useful for searching for sensitive seed aging signals for developing tools to monitor seed viability under storage.

No MeSH data available.


No significant association observed between estimates of germination rate and aleurone cells average diameter in naturally aged and AA wheat samples. Error bar indicates standard error.
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Figure 6: No significant association observed between estimates of germination rate and aleurone cells average diameter in naturally aged and AA wheat samples. Error bar indicates standard error.

Mentions: We quantified the scutellum changes by measuring scutellum and aleurone nuclei intensities, and determined the association between sample germination and nuclei intensity. It was found that an increase in nuclei staining intensity was positively associated with higher germination in NA and AA wheat seed samples (Figure 4). Similarly, we measured the scutellum (SE and SP) nuclei length and width and estimated the length to width ratios for the NA wheat seed samples. It was found that an increase in nuclei length to width ratios was negatively associated with increased germination for the NA wheat seed samples (Figure 5). However, the ratio measurement was not made for the AA seed samples, as longer AA treatments resulted in the loss of cellular contents and consequently fewer cells with nuclei were available for measurement. Also, we measured the changes in diameter of aleurone cells for both NA and AA wheat seed samples and found a non-significant association between the changes in aleurone cell diameter and germination rate (Figure 6).


The Associative Changes in Scutellum Nuclear Content and Morphology with Viability Loss of Naturally Aged and Accelerated Aging Wheat ( Triticum aestivum ) Seeds
No significant association observed between estimates of germination rate and aleurone cells average diameter in naturally aged and AA wheat samples. Error bar indicates standard error.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC5037135&req=5

Figure 6: No significant association observed between estimates of germination rate and aleurone cells average diameter in naturally aged and AA wheat samples. Error bar indicates standard error.
Mentions: We quantified the scutellum changes by measuring scutellum and aleurone nuclei intensities, and determined the association between sample germination and nuclei intensity. It was found that an increase in nuclei staining intensity was positively associated with higher germination in NA and AA wheat seed samples (Figure 4). Similarly, we measured the scutellum (SE and SP) nuclei length and width and estimated the length to width ratios for the NA wheat seed samples. It was found that an increase in nuclei length to width ratios was negatively associated with increased germination for the NA wheat seed samples (Figure 5). However, the ratio measurement was not made for the AA seed samples, as longer AA treatments resulted in the loss of cellular contents and consequently fewer cells with nuclei were available for measurement. Also, we measured the changes in diameter of aleurone cells for both NA and AA wheat seed samples and found a non-significant association between the changes in aleurone cell diameter and germination rate (Figure 6).

View Article: PubMed Central - PubMed

ABSTRACT

Timely prediction of seed viability loss over long-term storage represents a challenge in management and conservation of ex situ plant genetic resources. However, little attention has been paid to study the process of seed deterioration and seed aging signals under storage. An attempt was made here to investigate morphological and molecular changes in the scutellum and aleurone sections of naturally or artificially aged wheat seeds using TUNEL assay and DAPI staining. Twelve wheat genotypes or samples exposed to natural ageing (NA) or accelerated ageing (AA) were assayed and these samples had germination rates ranging from 11 to 93%. The assayed samples showed substantial changes in scutellum, but not aleurone. The nuclei observed in the majority of the scutellum cells of the NA seed samples of lower germination rates were longer in size and less visible, while the scutellum cell morphology or arrangement remained unchanged. In contrast, longer AA treatments resulted in the loss of scutellum cell structure, collapse of cell layers, and disappearance of honey comb arrangements. These nuclei and structural changes were consistent with the DNA assessments of nuclear alternations for the selected wheat samples. Interestingly, the sample seed germination loss was found to be associated with the reductions in the scutellum nuclear content and with the increases in the scutellum nuclei length to width ratio. These findings are significant for understanding the process of wheat seed deterioration and are also useful for searching for sensitive seed aging signals for developing tools to monitor seed viability under storage.

No MeSH data available.