Phytocystatins are a well-characterized class of naturally occurring protease inhibitors that prevent the catalysis of papain-like cysteine proteases. The action of cystatins in stress tolerance has been studied intensively, but relatively little is known about their functions in plants during leaf senescence. Here, we examined the potential roles of the apple cystatin, MpCYS4, in leaf photosyn...

During natural or dark-induced senescence, chlorophyll degradation causes leaf yellowing. Recent evidence indicates that chlorophyll catabolic enzymes (CCEs) interact with the photosynthetic apparatus; for example, five CCEs (NYC1, NOL, PPH, PAO and RCCR) interact with LHCII. STAY-GREEN (SGR) and CCEs interact with one another in senescing chloroplasts; this interaction may allow metabolic chan...

Grain production of rice (Oryza sativa L.) is a top priority in ensuring food security for human beings. One of the approaches to increase yield is to delay leaf senescence and to extend the available time for photosynthesis. MicroRNAs (miRNAs) are key regulators of aging and cellular senescence in eukaryotes. Here, to help understand their biological role in rice leaf senescence, we report ide...

Leaf senescence is a programmed developmental process governed by various endogenous and exogenous factors, such as the plant developmental stage, leaf age, phytohormone levels, darkness, and exposure to stresses. It was found that, in addition to its well-documented role in the enhancement of plant frost tolerance, overexpression of the C-repeat/dehydration responsive element binding factor 2 ...

An individually darkened leaf model was used to study protein changes in the Arabidopsis mutant stay-green1 (sgr1) to partially mimic the process of leaf covering senescence that occurs naturally in the shaded rosettes of Arabidopsis plants. Utilizing this controlled and predictable induced senescence model has allowed the direct comparison of sgr1 with Col-0 during the developmental period pre...

Leaf senescence varies greatly among genotypes of cotton (Gossypium hirsutium L), possibly due to the different expression of senescence-related genes. To determine genes involved in leaf senescence, we performed genome-wide transcriptional profiling of the main-stem leaves of an early- (K1) and a late-senescence (K2) cotton line at 110 day after planting (DAP) using the Solexa technology. The ...

Regulatory processes controlling traits such as anthesis timing and whole-plant senescence are of primary importance for reproductive success and for crop quality and yield. It has previously been demonstrated that the presence of alleles associated with high grain protein content (GPC) at a locus on barley chromosome six leads to accelerated leaf senescence, and to strong (>10-fold) up-regulat...

In field conditions, especially in arid and semi-arid areas, tea plants are often simultaneously exposed to various abiotic stresses such as cold and drought, which have profound effects on leaf senescence process and tea quality. However, most studies of gene expression in stress responses focus on a single inciting agent, and the confounding effect of multiple stresses on crop quality and lea...

Leaf senescence is a complex biological process and defense responses play vital role for rice development, their molecular mechanisms, however, remain elusive in rice. We herein reported a rice mutant spotted leaf 32 (spl32) derived from a rice cultivar 9311 by radiation. The spl32 plants displayed early leaf senescence, identified by disintegration of chloroplasts as cellular evidence, dramat...

Leaf senescence in plants involves both positive and negative transcriptional regulation. In this work, we show evidence for the single-stranded DNA-binding protein WHIRLY1 (WHY1) that functions as an upstream suppressor of WRKY53 in a developmental stage-dependent manner during leaf senescence in Arabidopsis (Arabidopsis thaliana). The why1 mutant displayed an early-senescence phenotype. In th...