Detection of DNA ladder during cotyledon senescence in cotton

Abstract

The asynchronous programmed cell death (PCD) in different regions of the cotton cotyledon was studied during senescence. We showed that changes in chlorophyll contents do not occur at the same time in different parts of the cotyledon. By using light microscopy (LM) and the terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick end in situ labelling (TUNEL) methods, the symptoms of cell death were detected in cotyledon margins earlier than in the central part. DNA ladders were detected by gel electrophoresis in senescent cotyledon margins and in the centre respectively, but not in the whole cotyledons.

Nitric oxide induces cotyledon senescence involving co-operation of the NES1/MAD1 and EIN2-associated ORE1 signalling pathways in Arabidopsis

“…Previous studies have focused on characterizing age-dependent cotyledon senescence in different plant species, such as soybean, cucumber, cotton, and pumpkin (Bick and Strehler, 1971; Kanazawa et al , 2000; Xie et al , 2008; Ananieva et al , 2008 b ) and light irradiation accelerated cotyledon senescence (Watanabe et al , 1994; Wilhelmová et al , 2004). In this study, the phenotype of nitric oxide-induced cotyledon senescence was investigated and the nes1 mutant was characterized as having early cotyledon senescence which was induced by nitric oxide.…”

Programmed cell death during development of cowpea (Vigna unguiculata (L.) Walp.) seed coat

“…Other examples of asynchronous cell death have been reported in cotton cotyledons during germination as well as DNA fragmentation (Xie et al . ) and asymmetric PCD in tomato leaf and flower abscission zone (Bar‐Dror et al . ).…”

“…), in endosperm cells of tomato seed (De Bonno & Greenwood ), during germination of cotton cotyledons (Xie et al . ), in quinoa perisperm development (López‐Fernández & Maldonado ) and in stipular colleters of Alseis pickelli (Tulli et al . ), among others.…”

“…During plant development, cells or tissues that grow up with transitory functions may undergo PCD, contributing to morphogenic or anatomical modelling. Developmental PCD occurs in vascular bundles during differentiation (Bonke et al 2003;Kozela & Regan 2003); in preventing self-pollination in Papaver rhoeas flowers (Thomas & Franklin-Tong 2004;Bosch & Franklin-Tong 2007); in primary roots of the cacti Stenocereus gummosus and Pachycereus pringlei (Shishkova & Dubrovsky 2005); during leaf morphogenesis in Aponogeton madagascariensis (Gunawardena et al 2004) and Monstera obliqua (Gunawardena et al 2005); at early developmental stages of Arabidopsis seed coat formation (Nakaune et al 2005), during tomato leaf abscission (Bar-Dror et al 2011); at initial developmental stages of Brassica napus seed inner integuments (Wan et al 2002); in suspensor cells at late stages of embryo development of Phaseolus coccineus (Yeung & Clutter 1979;Lombardi et al 2007); in somatic embryogenesis of Picea abies (Filonova et al 2000); in embryo elimination in polyembryonic seeds of Pinus silvestris (Filonova et al 2002); and in cotton cotyledons during senescence (Xie et al 2008), among others.…”

Senescence-Associated Programmed Cell Death

“…In common with leaves, senescence and PCD in cotyledons are not uniform across the organ. Thus, the fi rst signs of PCD, using TUNEL staining as a marker, were seen in the margins of cotton cotyledons [ 138 ] followed later by the centre. The asynchrony of PCD is also evident in other organs such as siliques and petals.…”